In the Linux kernel, the following vulnerability has been resolved:
mm/MADV_COLLAPSE: catch !none !huge !bad pmd lookups
In commit 34488399fa08 ("mm/madvise: add file and shmem support to
MADV_COLLAPSE") we make the following change to find_pmd_or_thp_or_none():
- if (!pmd_present(pmde))
- return SCAN_PMD_NULL;
+ if (pmd_none(pmde))
+ return SCAN_PMD_NONE;
This was for-use by MADV_COLLAPSE file/shmem codepaths, where
MADV_COLLAPSE might identify a pte-mapped hugepage, only to have
khugepaged race-in, free the pte table, and clear the pmd. Such codepaths
include:
A) If we find a suitably-aligned compound page of order HPAGE_PMD_ORDER
already in the pagecache.
B) In retract_page_tables(), if we fail to grab mmap_lock for the target
mm/address.
In these cases, collapse_pte_mapped_thp() really does expect a none (not
just !present) pmd, and we want to suitably identify that case separate
from the case where no pmd is found, or it's a bad-pmd (of course, many
things could happen once we drop mmap_lock, and the pmd could plausibly
undergo multiple transitions due to intervening fault, split, etc).
Regardless, the code is prepared install a huge-pmd only when the existing
pmd entry is either a genuine pte-table-mapping-pmd, or the none-pmd.
However, the commit introduces a logical hole; namely, that we've allowed
!none- && !huge- && !bad-pmds to be classified as genuine
pte-table-mapping-pmds. One such example that could leak through are swap
entries. The pmd values aren't checked again before use in
pte_offset_map_lock(), which is expecting nothing less than a genuine
pte-table-mapping-pmd.
We want to put back the !pmd_present() check (below the pmd_none() check),
but need to be careful to deal with subtleties in pmd transitions and
treatments by various arch.
The issue is that __split_huge_pmd_locked() temporarily clears the present
bit (or otherwise marks the entry as invalid), but pmd_present() and
pmd_trans_huge() still need to return true while the pmd is in this
transitory state. For example, x86's pmd_present() also checks the
_PAGE_PSE , riscv's version also checks the _PAGE_LEAF bit, and arm64 also
checks a PMD_PRESENT_INVALID bit.
Covering all 4 cases for x86 (all checks done on the same pmd value):
1) pmd_present() && pmd_trans_huge()
All we actually know here is that the PSE bit is set. Either:
a) We aren't racing with __split_huge_page(), and PRESENT or PROTNONE
is set.
=> huge-pmd
b) We are currently racing with __split_huge_page(). The danger here
is that we proceed as-if we have a huge-pmd, but really we are
looking at a pte-mapping-pmd. So, what is the risk of this
danger?
The only relevant path is:
madvise_collapse() -> collapse_pte_mapped_thp()
Where we might just incorrectly report back "success", when really
the memory isn't pmd-backed. This is fine, since split could
happen immediately after (actually) successful madvise_collapse().
So, it should be safe to just assume huge-pmd here.
2) pmd_present() && !pmd_trans_huge()
Either:
a) PSE not set and either PRESENT or PROTNONE is.
=> pte-table-mapping pmd (or PROT_NONE)
b) devmap. This routine can be called immediately after
unlocking/locking mmap_lock -- or called with no locks held (see
khugepaged_scan_mm_slot()), so previous VMA checks have since been
invalidated.
3) !pmd_present() && pmd_trans_huge()
Not possible.
4) !pmd_present() && !pmd_trans_huge()
Neither PRESENT nor PROTNONE set
=> not present
I've checked all archs that implement pmd_trans_huge() (arm64, riscv,
powerpc, longarch, x86, mips, s390) and this logic roughly translates
(though devmap treatment is unique to x86 and powerpc, and (3) doesn't
necessarily hold in general -- but that doesn't matter since
!pmd_present() always takes failure path).
Also, add a comment above find_pmd_or_thp_or_none()
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
Squashfs: fix handling and sanity checking of xattr_ids count
A Sysbot [1] corrupted filesystem exposes two flaws in the handling and
sanity checking of the xattr_ids count in the filesystem. Both of these
flaws cause computation overflow due to incorrect typing.
In the corrupted filesystem the xattr_ids value is 4294967071, which
stored in a signed variable becomes the negative number -225.
Flaw 1 (64-bit systems only):
The signed integer xattr_ids variable causes sign extension.
This causes variable overflow in the SQUASHFS_XATTR_*(A) macros. The
variable is first multiplied by sizeof(struct squashfs_xattr_id) where the
type of the sizeof operator is "unsigned long".
On a 64-bit system this is 64-bits in size, and causes the negative number
to be sign extended and widened to 64-bits and then become unsigned. This
produces the very large number 18446744073709548016 or 2^64 - 3600. This
number when rounded up by SQUASHFS_METADATA_SIZE - 1 (8191 bytes) and
divided by SQUASHFS_METADATA_SIZE overflows and produces a length of 0
(stored in len).
Flaw 2 (32-bit systems only):
On a 32-bit system the integer variable is not widened by the unsigned
long type of the sizeof operator (32-bits), and the signedness of the
variable has no effect due it always being treated as unsigned.
The above corrupted xattr_ids value of 4294967071, when multiplied
overflows and produces the number 4294963696 or 2^32 - 3400. This number
when rounded up by SQUASHFS_METADATA_SIZE - 1 (8191 bytes) and divided by
SQUASHFS_METADATA_SIZE overflows again and produces a length of 0.
The effect of the 0 length computation:
In conjunction with the corrupted xattr_ids field, the filesystem also has
a corrupted xattr_table_start value, where it matches the end of
filesystem value of 850.
This causes the following sanity check code to fail because the
incorrectly computed len of 0 matches the incorrect size of the table
reported by the superblock (0 bytes).
len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
indexes = SQUASHFS_XATTR_BLOCKS(*xattr_ids);
/*
* The computed size of the index table (len bytes) should exactly
* match the table start and end points
*/
start = table_start + sizeof(*id_table);
end = msblk->bytes_used;
if (len != (end - start))
return ERR_PTR(-EINVAL);
Changing the xattr_ids variable to be "usigned int" fixes the flaw on a
64-bit system. This relies on the fact the computation is widened by the
unsigned long type of the sizeof operator.
Casting the variable to u64 in the above macro fixes this flaw on a 32-bit
system.
It also means 64-bit systems do not implicitly rely on the type of the
sizeof operator to widen the computation.
[1] https://lore.kernel.org/lkml/000000000000cd44f005f1a0f17f@google.com/
In the Linux kernel, the following vulnerability has been resolved:
mm/swapfile: add cond_resched() in get_swap_pages()
The softlockup still occurs in get_swap_pages() under memory pressure. 64
CPU cores, 64GB memory, and 28 zram devices, the disksize of each zram
device is 50MB with same priority as si. Use the stress-ng tool to
increase memory pressure, causing the system to oom frequently.
The plist_for_each_entry_safe() loops in get_swap_pages() could reach tens
of thousands of times to find available space (extreme case:
cond_resched() is not called in scan_swap_map_slots()). Let's add
cond_resched() into get_swap_pages() when failed to find available space
to avoid softlockup.
In the Linux kernel, the following vulnerability has been resolved:
nvmem: core: fix cleanup after dev_set_name()
If dev_set_name() fails, we leak nvmem->wp_gpio as the cleanup does not
put this. While a minimal fix for this would be to add the gpiod_put()
call, we can do better if we split device_register(), and use the
tested nvmem_release() cleanup code by initialising the device early,
and putting the device.
This results in a slightly larger fix, but results in clear code.
Note: this patch depends on "nvmem: core: initialise nvmem->id early"
and "nvmem: core: remove nvmem_config wp_gpio".
[Srini: Fixed subject line and error code handing with wp_gpio while applying.]
In the Linux kernel, the following vulnerability has been resolved:
bpf: Skip invalid kfunc call in backtrack_insn
The verifier skips invalid kfunc call in check_kfunc_call(), which
would be captured in fixup_kfunc_call() if such insn is not eliminated
by dead code elimination. However, this can lead to the following
warning in backtrack_insn(), also see [1]:
------------[ cut here ]------------
verifier backtracking bug
WARNING: CPU: 6 PID: 8646 at kernel/bpf/verifier.c:2756 backtrack_insn
kernel/bpf/verifier.c:2756
__mark_chain_precision kernel/bpf/verifier.c:3065
mark_chain_precision kernel/bpf/verifier.c:3165
adjust_reg_min_max_vals kernel/bpf/verifier.c:10715
check_alu_op kernel/bpf/verifier.c:10928
do_check kernel/bpf/verifier.c:13821 [inline]
do_check_common kernel/bpf/verifier.c:16289
[...]
So make backtracking conservative with this by returning ENOTSUPP.
[1] https://lore.kernel.org/bpf/CACkBjsaXNceR8ZjkLG=dT3P=4A8SBsg0Z5h5PWLryF5=ghKq=g@mail.gmail.com/
In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: fix PTE marker handling in hugetlb_change_protection()
Patch series "mm/hugetlb: uffd-wp fixes for hugetlb_change_protection()".
Playing with virtio-mem and background snapshots (using uffd-wp) on
hugetlb in QEMU, I managed to trigger a VM_BUG_ON(). Looking into the
details, hugetlb_change_protection() seems to not handle uffd-wp correctly
in all cases.
Patch #1 fixes my test case. I don't have reproducers for patch #2, as it
requires running into migration entries.
I did not yet check in detail yet if !hugetlb code requires similar care.
This patch (of 2):
There are two problematic cases when stumbling over a PTE marker in
hugetlb_change_protection():
(1) We protect an uffd-wp PTE marker a second time using uffd-wp: we will
end up in the "!huge_pte_none(pte)" case and mess up the PTE marker.
(2) We unprotect a uffd-wp PTE marker: we will similarly end up in the
"!huge_pte_none(pte)" case even though we cleared the PTE, because
the "pte" variable is stale. We'll mess up the PTE marker.
For example, if we later stumble over such a "wrongly modified" PTE marker,
we'll treat it like a present PTE that maps some garbage page.
This can, for example, be triggered by mapping a memfd backed by huge
pages, registering uffd-wp, uffd-wp'ing an unmapped page and (a)
uffd-wp'ing it a second time; or (b) uffd-unprotecting it; or (c)
unregistering uffd-wp. Then, ff we trigger fallocate(FALLOC_FL_PUNCH_HOLE)
on that file range, we will run into a VM_BUG_ON:
[ 195.039560] page:00000000ba1f2987 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0
[ 195.039565] flags: 0x7ffffc0001000(reserved|node=0|zone=0|lastcpupid=0x1fffff)
[ 195.039568] raw: 0007ffffc0001000 ffffe742c0000008 ffffe742c0000008 0000000000000000
[ 195.039569] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
[ 195.039569] page dumped because: VM_BUG_ON_PAGE(compound && !PageHead(page))
[ 195.039573] ------------[ cut here ]------------
[ 195.039574] kernel BUG at mm/rmap.c:1346!
[ 195.039579] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 195.039581] CPU: 7 PID: 4777 Comm: qemu-system-x86 Not tainted 6.0.12-200.fc36.x86_64 #1
[ 195.039583] Hardware name: LENOVO 20WNS1F81N/20WNS1F81N, BIOS N35ET50W (1.50 ) 09/15/2022
[ 195.039584] RIP: 0010:page_remove_rmap+0x45b/0x550
[ 195.039588] Code: [...]
[ 195.039589] RSP: 0018:ffffbc03c3633ba8 EFLAGS: 00010292
[ 195.039591] RAX: 0000000000000040 RBX: ffffe742c0000000 RCX: 0000000000000000
[ 195.039592] RDX: 0000000000000002 RSI: ffffffff8e7aac1a RDI: 00000000ffffffff
[ 195.039592] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffbc03c3633a08
[ 195.039593] R10: 0000000000000003 R11: ffffffff8f146328 R12: ffff9b04c42754b0
[ 195.039594] R13: ffffffff8fcc6328 R14: ffffbc03c3633c80 R15: ffff9b0484ab9100
[ 195.039595] FS: 00007fc7aaf68640(0000) GS:ffff9b0bbf7c0000(0000) knlGS:0000000000000000
[ 195.039596] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 195.039597] CR2: 000055d402c49110 CR3: 0000000159392003 CR4: 0000000000772ee0
[ 195.039598] PKRU: 55555554
[ 195.039599] Call Trace:
[ 195.039600] <TASK>
[ 195.039602] __unmap_hugepage_range+0x33b/0x7d0
[ 195.039605] unmap_hugepage_range+0x55/0x70
[ 195.039608] hugetlb_vmdelete_list+0x77/0xa0
[ 195.039611] hugetlbfs_fallocate+0x410/0x550
[ 195.039612] ? _raw_spin_unlock_irqrestore+0x23/0x40
[ 195.039616] vfs_fallocate+0x12e/0x360
[ 195.039618] __x64_sys_fallocate+0x40/0x70
[ 195.039620] do_syscall_64+0x58/0x80
[ 195.039623] ? syscall_exit_to_user_mode+0x17/0x40
[ 195.039624] ? do_syscall_64+0x67/0x80
[ 195.039626] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 195.039628] RIP: 0033:0x7fc7b590651f
[ 195.039653] Code: [...]
[ 195.039654] RSP: 002b:00007fc7aaf66e70 EFLAGS: 00000293 ORIG_RAX: 000000000000011d
[ 195.039655] RAX: ffffffffffffffda RBX: 0000558ef4b7f370 RCX: 00007fc7b590651f
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
reset: uniphier-glue: Fix possible null-ptr-deref
It will cause null-ptr-deref when resource_size(res) invoked,
if platform_get_resource() returns NULL.
In the Linux kernel, the following vulnerability has been resolved:
EDAC/highbank: Fix memory leak in highbank_mc_probe()
When devres_open_group() fails, it returns -ENOMEM without freeing memory
allocated by edac_mc_alloc().
Call edac_mc_free() on the error handling path to avoid a memory leak.
[ bp: Massage commit message. ]
In the Linux kernel, the following vulnerability has been resolved:
phy: usb: sunplus: Fix potential null-ptr-deref in sp_usb_phy_probe()
sp_usb_phy_probe() will call platform_get_resource_byname() that may fail
and return NULL. devm_ioremap() will use usbphy->moon4_res_mem->start as
input, which may causes null-ptr-deref. Check the ret value of
platform_get_resource_byname() to avoid the null-ptr-deref.
In the Linux kernel, the following vulnerability has been resolved:
device property: fix of node refcount leak in fwnode_graph_get_next_endpoint()
The 'parent' returned by fwnode_graph_get_port_parent()
with refcount incremented when 'prev' is not NULL, it
needs be put when finish using it.
Because the parent is const, introduce a new variable to
store the returned fwnode, then put it before returning
from fwnode_graph_get_next_endpoint().
In the Linux kernel, the following vulnerability has been resolved:
w1: fix WARNING after calling w1_process()
I got the following WARNING message while removing driver(ds2482):
------------[ cut here ]------------
do not call blocking ops when !TASK_RUNNING; state=1 set at [<000000002d50bfb6>] w1_process+0x9e/0x1d0 [wire]
WARNING: CPU: 0 PID: 262 at kernel/sched/core.c:9817 __might_sleep+0x98/0xa0
CPU: 0 PID: 262 Comm: w1_bus_master1 Tainted: G N 6.1.0-rc3+ #307
RIP: 0010:__might_sleep+0x98/0xa0
Call Trace:
exit_signals+0x6c/0x550
do_exit+0x2b4/0x17e0
kthread_exit+0x52/0x60
kthread+0x16d/0x1e0
ret_from_fork+0x1f/0x30
The state of task is set to TASK_INTERRUPTIBLE in loop in w1_process(),
set it to TASK_RUNNING when it breaks out of the loop to avoid the
warning.
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: CPPC: Add u64 casts to avoid overflowing
The fields of the _CPC object are unsigned 32-bits values.
To avoid overflows while using _CPC's values, add 'u64' casts.
In the Linux kernel, the following vulnerability has been resolved:
i2c: designware: use casting of u64 in clock multiplication to avoid overflow
In functions i2c_dw_scl_lcnt() and i2c_dw_scl_hcnt() may have overflow
by depending on the values of the given parameters including the ic_clk.
For example in our use case where ic_clk is larger than one million,
multiplication of ic_clk * 4700 will result in 32 bit overflow.
Add cast of u64 to the calculation to avoid multiplication overflow, and
use the corresponding define for divide.
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/amd: fix potential integer overflow on shift of a int
The left shift of int 32 bit integer constant 1 is evaluated using 32 bit
arithmetic and then passed as a 64 bit function argument. In the case where
i is 32 or more this can lead to an overflow. Avoid this by shifting
using the BIT_ULL macro instead.
In the Linux kernel, the following vulnerability has been resolved:
erofs/zmap.c: Fix incorrect offset calculation
Effective offset to add to length was being incorrectly calculated,
which resulted in iomap->length being set to 0, triggering a WARN_ON
in iomap_iter_done().
Fix that, and describe it in comments.
This was reported as a crash by syzbot under an issue about a warning
encountered in iomap_iter_done(), but unrelated to erofs.
C reproducer: https://syzkaller.appspot.com/text?tag=ReproC&x=1037a6b2880000
Kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=e2021a61197ebe02
Dashboard link: https://syzkaller.appspot.com/bug?extid=a8e049cd3abd342936b6
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: imx-sdma: Fix a possible memory leak in sdma_transfer_init
If the function sdma_load_context() fails, the sdma_desc will be
freed, but the allocated desc->bd is forgot to be freed.
We already met the sdma_load_context() failure case and the log as
below:
[ 450.699064] imx-sdma 30bd0000.dma-controller: Timeout waiting for CH0 ready
...
In this case, the desc->bd will not be freed without this change.
In the Linux kernel, the following vulnerability has been resolved:
fpga: m10bmc-sec: Fix probe rollback
Handle probe error rollbacks properly to avoid leaks.
In the Linux kernel, the following vulnerability has been resolved:
mm/uffd: fix pte marker when fork() without fork event
Patch series "mm: Fixes on pte markers".
Patch 1 resolves the syzkiller report from Pengfei.
Patch 2 further harden pte markers when used with the recent swapin error
markers. The major case is we should persist a swapin error marker after
fork(), so child shouldn't read a corrupted page.
This patch (of 2):
When fork(), dst_vma is not guaranteed to have VM_UFFD_WP even if src may
have it and has pte marker installed. The warning is improper along with
the comment. The right thing is to inherit the pte marker when needed, or
keep the dst pte empty.
A vague guess is this happened by an accident when there's the prior patch
to introduce src/dst vma into this helper during the uffd-wp feature got
developed and I probably messed up in the rebase, since if we replace
dst_vma with src_vma the warning & comment it all makes sense too.
Hugetlb did exactly the right here (copy_hugetlb_page_range()). Fix the
general path.
Reproducer:
https://github.com/xupengfe/syzkaller_logs/blob/main/221208_115556_copy_page_range/repro.c
Bugzilla report: https://bugzilla.kernel.org/show_bug.cgi?id=216808
In the Linux kernel, the following vulnerability has been resolved:
ovl: Use "buf" flexible array for memcpy() destination
The "buf" flexible array needs to be the memcpy() destination to avoid
false positive run-time warning from the recent FORTIFY_SOURCE
hardening:
memcpy: detected field-spanning write (size 93) of single field "&fh->fb"
at fs/overlayfs/export.c:799 (size 21)
In the Linux kernel, the following vulnerability has been resolved:
f2fs: initialize locks earlier in f2fs_fill_super()
syzbot is reporting lockdep warning at f2fs_handle_error() [1], for
spin_lock(&sbi->error_lock) is called before spin_lock_init() is called.
For safe locking in error handling, move initialization of locks (and
obvious structures) in f2fs_fill_super() to immediately after memory
allocation.
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Always check inode size of inline inodes
Check if the inode size of stuffed (inline) inodes is within the allowed
range when reading inodes from disk (gfs2_dinode_in()). This prevents
us from on-disk corruption.
The two checks in stuffed_readpage() and gfs2_unstuffer_page() that just
truncate inline data to the maximum allowed size don't actually make
sense, and they can be removed now as well.
In the Linux kernel, the following vulnerability has been resolved:
can: j1939: fix errant WARN_ON_ONCE in j1939_session_deactivate
The conclusion "j1939_session_deactivate() should be called with a
session ref-count of at least 2" is incorrect. In some concurrent
scenarios, j1939_session_deactivate can be called with the session
ref-count less than 2. But there is not any problem because it
will check the session active state before session putting in
j1939_session_deactivate_locked().
Here is the concurrent scenario of the problem reported by syzbot
and my reproduction log.
cpu0 cpu1
j1939_xtp_rx_eoma
j1939_xtp_rx_abort_one
j1939_session_get_by_addr [kref == 2]
j1939_session_get_by_addr [kref == 3]
j1939_session_deactivate [kref == 2]
j1939_session_put [kref == 1]
j1939_session_completed
j1939_session_deactivate
WARN_ON_ONCE(kref < 2)
=====================================================
WARNING: CPU: 1 PID: 21 at net/can/j1939/transport.c:1088 j1939_session_deactivate+0x5f/0x70
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 5.14.0-rc7+ #32
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:j1939_session_deactivate+0x5f/0x70
Call Trace:
j1939_session_deactivate_activate_next+0x11/0x28
j1939_xtp_rx_eoma+0x12a/0x180
j1939_tp_recv+0x4a2/0x510
j1939_can_recv+0x226/0x380
can_rcv_filter+0xf8/0x220
can_receive+0x102/0x220
? process_backlog+0xf0/0x2c0
can_rcv+0x53/0xf0
__netif_receive_skb_one_core+0x67/0x90
? process_backlog+0x97/0x2c0
__netif_receive_skb+0x22/0x80
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in yudleethemes Whitish Lite allows Stored XSS.This issue affects Whitish Lite: from n/a through 2.1.13.
Pitchfork is a preforking HTTP server for Rack applications. Versions prior to 0.11.0 are vulnerable to HTTP Response Header Injection when used in conjunction with Rack 3. The issue was fixed in Pitchfork release 0.11.0. No known workarounds are available.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Themeisle Orbit Fox by ThemeIsle themeisle-companion allows Stored XSS.This issue affects Orbit Fox by ThemeIsle: from n/a through <= 2.10.44.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in weDevs WP Project Manager wedevs-project-manager allows Stored XSS.This issue affects WP Project Manager: from n/a through <= 2.6.22.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Syed Balkhi aThemes Addons for Elementor athemes-addons-for-elementor-lite allows Stored XSS.This issue affects aThemes Addons for Elementor: from n/a through <= 1.0.8.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix the recovery flow of the UMR QP
This patch addresses an issue in the recovery flow of the UMR QP,
ensuring tasks do not get stuck, as highlighted by the call trace [1].
During recovery, before transitioning the QP to the RESET state, the
software must wait for all outstanding WRs to complete.
Failing to do so can cause the firmware to skip sending some flushed
CQEs with errors and simply discard them upon the RESET, as per the IB
specification.
This race condition can result in lost CQEs and tasks becoming stuck.
To resolve this, the patch sends a final WR which serves only as a
barrier before moving the QP state to RESET.
Once a CQE is received for that final WR, it guarantees that no
outstanding WRs remain, making it safe to transition the QP to RESET and
subsequently back to RTS, restoring proper functionality.
Note:
For the barrier WR, we simply reuse the failed and ready WR.
Since the QP is in an error state, it will only receive
IB_WC_WR_FLUSH_ERR. However, as it serves only as a barrier we don't
care about its status.
[1]
INFO: task rdma_resource_l:1922 blocked for more than 120 seconds.
Tainted: G W 6.12.0-rc7+ #1626
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:rdma_resource_l state:D stack:0 pid:1922 tgid:1922 ppid:1369
flags:0x00004004
Call Trace:
<TASK>
__schedule+0x420/0xd30
schedule+0x47/0x130
schedule_timeout+0x280/0x300
? mark_held_locks+0x48/0x80
? lockdep_hardirqs_on_prepare+0xe5/0x1a0
wait_for_completion+0x75/0x130
mlx5r_umr_post_send_wait+0x3c2/0x5b0 [mlx5_ib]
? __pfx_mlx5r_umr_done+0x10/0x10 [mlx5_ib]
mlx5r_umr_revoke_mr+0x93/0xc0 [mlx5_ib]
__mlx5_ib_dereg_mr+0x299/0x520 [mlx5_ib]
? _raw_spin_unlock_irq+0x24/0x40
? wait_for_completion+0xfe/0x130
? rdma_restrack_put+0x63/0xe0 [ib_core]
ib_dereg_mr_user+0x5f/0x120 [ib_core]
? lock_release+0xc6/0x280
destroy_hw_idr_uobject+0x1d/0x60 [ib_uverbs]
uverbs_destroy_uobject+0x58/0x1d0 [ib_uverbs]
uobj_destroy+0x3f/0x70 [ib_uverbs]
ib_uverbs_cmd_verbs+0x3e4/0xbb0 [ib_uverbs]
? __pfx_uverbs_destroy_def_handler+0x10/0x10 [ib_uverbs]
? __lock_acquire+0x64e/0x2080
? mark_held_locks+0x48/0x80
? find_held_lock+0x2d/0xa0
? lock_acquire+0xc1/0x2f0
? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]
? __fget_files+0xc3/0x1b0
ib_uverbs_ioctl+0xe7/0x170 [ib_uverbs]
? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]
__x64_sys_ioctl+0x1b0/0xa70
do_syscall_64+0x6b/0x140
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f99c918b17b
RSP: 002b:00007ffc766d0468 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
RAX: ffffffffffffffda RBX: 00007ffc766d0578 RCX:
00007f99c918b17b
RDX: 00007ffc766d0560 RSI: 00000000c0181b01 RDI:
0000000000000003
RBP: 00007ffc766d0540 R08: 00007f99c8f99010 R09:
000000000000bd7e
R10: 00007f99c94c1c70 R11: 0000000000000246 R12:
00007ffc766d0530
R13: 000000000000001c R14: 0000000040246a80 R15:
0000000000000000
</TASK>
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Add RCU read lock protection to perf_iterate_ctx()
The perf_iterate_ctx() function performs RCU list traversal but
currently lacks RCU read lock protection. This causes lockdep warnings
when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y:
WARNING: suspicious RCU usage
kernel/events/core.c:8168 RCU-list traversed in non-reader section!!
Call Trace:
lockdep_rcu_suspicious
? perf_event_addr_filters_apply
perf_iterate_ctx
perf_event_exec
begin_new_exec
? load_elf_phdrs
load_elf_binary
? lock_acquire
? find_held_lock
? bprm_execve
bprm_execve
do_execveat_common.isra.0
__x64_sys_execve
do_syscall_64
entry_SYSCALL_64_after_hwframe
This protection was previously present but was removed in commit
bd2756811766 ("perf: Rewrite core context handling"). Add back the
necessary rcu_read_lock()/rcu_read_unlock() pair around
perf_iterate_ctx() call in perf_event_exec().
[ mingo: Use scoped_guard() as suggested by Peter ]
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix implicit ODP hang on parent deregistration
Fix the destroy_unused_implicit_child_mr() to prevent hanging during
parent deregistration as of below [1].
Upon entering destroy_unused_implicit_child_mr(), the reference count
for the implicit MR parent is incremented using:
refcount_inc_not_zero().
A corresponding decrement must be performed if
free_implicit_child_mr_work() is not called.
The code has been updated to properly manage the reference count that
was incremented.
[1]
INFO: task python3:2157 blocked for more than 120 seconds.
Not tainted 6.12.0-rc7+ #1633
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:python3 state:D stack:0 pid:2157 tgid:2157 ppid:1685 flags:0x00000000
Call Trace:
<TASK>
__schedule+0x420/0xd30
schedule+0x47/0x130
__mlx5_ib_dereg_mr+0x379/0x5d0 [mlx5_ib]
? __pfx_autoremove_wake_function+0x10/0x10
ib_dereg_mr_user+0x5f/0x120 [ib_core]
? lock_release+0xc6/0x280
destroy_hw_idr_uobject+0x1d/0x60 [ib_uverbs]
uverbs_destroy_uobject+0x58/0x1d0 [ib_uverbs]
uobj_destroy+0x3f/0x70 [ib_uverbs]
ib_uverbs_cmd_verbs+0x3e4/0xbb0 [ib_uverbs]
? __pfx_uverbs_destroy_def_handler+0x10/0x10 [ib_uverbs]
? lock_acquire+0xc1/0x2f0
? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]
? ib_uverbs_ioctl+0x116/0x170 [ib_uverbs]
? lock_release+0xc6/0x280
ib_uverbs_ioctl+0xe7/0x170 [ib_uverbs]
? ib_uverbs_ioctl+0xcb/0x170 [ib_uverbs]
__x64_sys_ioctl+0x1b0/0xa70
? kmem_cache_free+0x221/0x400
do_syscall_64+0x6b/0x140
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f20f21f017b
RSP: 002b:00007ffcfc4a77c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffcfc4a78d8 RCX: 00007f20f21f017b
RDX: 00007ffcfc4a78c0 RSI: 00000000c0181b01 RDI: 0000000000000003
RBP: 00007ffcfc4a78a0 R08: 000056147d125190 R09: 00007f20f1f14c60
R10: 0000000000000001 R11: 0000000000000246 R12: 00007ffcfc4a7890
R13: 000000000000001c R14: 000056147d100fc0 R15: 00007f20e365c9d0
</TASK>
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Fix vport QoS cleanup on error
When enabling vport QoS fails, the scheduling node was never freed,
causing a leak.
Add the missing free and reset the vport scheduling node pointer to
NULL.
In the Linux kernel, the following vulnerability has been resolved:
uprobes: Reject the shared zeropage in uprobe_write_opcode()
We triggered the following crash in syzkaller tests:
BUG: Bad page state in process syz.7.38 pfn:1eff3
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1eff3
flags: 0x3fffff00004004(referenced|reserved|node=0|zone=1|lastcpupid=0x1fffff)
raw: 003fffff00004004 ffffe6c6c07bfcc8 ffffe6c6c07bfcc8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000fffffffe 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x32/0x50
bad_page+0x69/0xf0
free_unref_page_prepare+0x401/0x500
free_unref_page+0x6d/0x1b0
uprobe_write_opcode+0x460/0x8e0
install_breakpoint.part.0+0x51/0x80
register_for_each_vma+0x1d9/0x2b0
__uprobe_register+0x245/0x300
bpf_uprobe_multi_link_attach+0x29b/0x4f0
link_create+0x1e2/0x280
__sys_bpf+0x75f/0xac0
__x64_sys_bpf+0x1a/0x30
do_syscall_64+0x56/0x100
entry_SYSCALL_64_after_hwframe+0x78/0xe2
BUG: Bad rss-counter state mm:00000000452453e0 type:MM_FILEPAGES val:-1
The following syzkaller test case can be used to reproduce:
r2 = creat(&(0x7f0000000000)='./file0\x00', 0x8)
write$nbd(r2, &(0x7f0000000580)=ANY=[], 0x10)
r4 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x42, 0x0)
mmap$IORING_OFF_SQ_RING(&(0x7f0000ffd000/0x3000)=nil, 0x3000, 0x0, 0x12, r4, 0x0)
r5 = userfaultfd(0x80801)
ioctl$UFFDIO_API(r5, 0xc018aa3f, &(0x7f0000000040)={0xaa, 0x20})
r6 = userfaultfd(0x80801)
ioctl$UFFDIO_API(r6, 0xc018aa3f, &(0x7f0000000140))
ioctl$UFFDIO_REGISTER(r6, 0xc020aa00, &(0x7f0000000100)={{&(0x7f0000ffc000/0x4000)=nil, 0x4000}, 0x2})
ioctl$UFFDIO_ZEROPAGE(r5, 0xc020aa04, &(0x7f0000000000)={{&(0x7f0000ffd000/0x1000)=nil, 0x1000}})
r7 = bpf$PROG_LOAD(0x5, &(0x7f0000000140)={0x2, 0x3, &(0x7f0000000200)=ANY=[@ANYBLOB="1800000000120000000000000000000095"], &(0x7f0000000000)='GPL\x00', 0x7, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @fallback=0x30, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94)
bpf$BPF_LINK_CREATE_XDP(0x1c, &(0x7f0000000040)={r7, 0x0, 0x30, 0x1e, @val=@uprobe_multi={&(0x7f0000000080)='./file0\x00', &(0x7f0000000100)=[0x2], 0x0, 0x0, 0x1}}, 0x40)
The cause is that zero pfn is set to the PTE without increasing the RSS
count in mfill_atomic_pte_zeropage() and the refcount of zero folio does
not increase accordingly. Then, the operation on the same pfn is performed
in uprobe_write_opcode()->__replace_page() to unconditional decrease the
RSS count and old_folio's refcount.
Therefore, two bugs are introduced:
1. The RSS count is incorrect, when process exit, the check_mm() report
error "Bad rss-count".
2. The reserved folio (zero folio) is freed when folio->refcount is zero,
then free_pages_prepare->free_page_is_bad() report error
"Bad page state".
There is more, the following warning could also theoretically be triggered:
__replace_page()
-> ...
-> folio_remove_rmap_pte()
-> VM_WARN_ON_FOLIO(is_zero_folio(folio), folio)
Considering that uprobe hit on the zero folio is a very rare case, just
reject zero old folio immediately after get_user_page_vma_remote().
[ mingo: Cleaned up the changelog ]
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/userptr: fix EFAULT handling
Currently we treat EFAULT from hmm_range_fault() as a non-fatal error
when called from xe_vm_userptr_pin() with the idea that we want to avoid
killing the entire vm and chucking an error, under the assumption that
the user just did an unmap or something, and has no intention of
actually touching that memory from the GPU. At this point we have
already zapped the PTEs so any access should generate a page fault, and
if the pin fails there also it will then become fatal.
However it looks like it's possible for the userptr vma to still be on
the rebind list in preempt_rebind_work_func(), if we had to retry the
pin again due to something happening in the caller before we did the
rebind step, but in the meantime needing to re-validate the userptr and
this time hitting the EFAULT.
This explains an internal user report of hitting:
[ 191.738349] WARNING: CPU: 1 PID: 157 at drivers/gpu/drm/xe/xe_res_cursor.h:158 xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738551] Workqueue: xe-ordered-wq preempt_rebind_work_func [xe]
[ 191.738616] RIP: 0010:xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738690] Call Trace:
[ 191.738692] <TASK>
[ 191.738694] ? show_regs+0x69/0x80
[ 191.738698] ? __warn+0x93/0x1a0
[ 191.738703] ? xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738759] ? report_bug+0x18f/0x1a0
[ 191.738764] ? handle_bug+0x63/0xa0
[ 191.738767] ? exc_invalid_op+0x19/0x70
[ 191.738770] ? asm_exc_invalid_op+0x1b/0x20
[ 191.738777] ? xe_pt_stage_bind.constprop.0+0x60a/0x6b0 [xe]
[ 191.738834] ? ret_from_fork_asm+0x1a/0x30
[ 191.738849] bind_op_prepare+0x105/0x7b0 [xe]
[ 191.738906] ? dma_resv_reserve_fences+0x301/0x380
[ 191.738912] xe_pt_update_ops_prepare+0x28c/0x4b0 [xe]
[ 191.738966] ? kmemleak_alloc+0x4b/0x80
[ 191.738973] ops_execute+0x188/0x9d0 [xe]
[ 191.739036] xe_vm_rebind+0x4ce/0x5a0 [xe]
[ 191.739098] ? trace_hardirqs_on+0x4d/0x60
[ 191.739112] preempt_rebind_work_func+0x76f/0xd00 [xe]
Followed by NPD, when running some workload, since the sg was never
actually populated but the vma is still marked for rebind when it should
be skipped for this special EFAULT case. This is confirmed to fix the
user report.
v2 (MattB):
- Move earlier.
v3 (MattB):
- Update the commit message to make it clear that this indeed fixes the
issue.
(cherry picked from commit 6b93cb98910c826c2e2004942f8b060311e43618)
In the Linux kernel, the following vulnerability has been resolved:
usbnet: gl620a: fix endpoint checking in genelink_bind()
Syzbot reports [1] a warning in usb_submit_urb() triggered by
inconsistencies between expected and actually present endpoints
in gl620a driver. Since genelink_bind() does not properly
verify whether specified eps are in fact provided by the device,
in this case, an artificially manufactured one, one may get a
mismatch.
Fix the issue by resorting to a usbnet utility function
usbnet_get_endpoints(), usually reserved for this very problem.
Check for endpoints and return early before proceeding further if
any are missing.
[1] Syzbot report:
usb 5-1: Manufacturer: syz
usb 5-1: SerialNumber: syz
usb 5-1: config 0 descriptor??
gl620a 5-1:0.23 usb0: register 'gl620a' at usb-dummy_hcd.0-1, ...
------------[ cut here ]------------
usb 5-1: BOGUS urb xfer, pipe 3 != type 1
WARNING: CPU: 2 PID: 1841 at drivers/usb/core/urb.c:503 usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503
Modules linked in:
CPU: 2 UID: 0 PID: 1841 Comm: kworker/2:2 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: mld mld_ifc_work
RIP: 0010:usb_submit_urb+0xe4b/0x1730 drivers/usb/core/urb.c:503
...
Call Trace:
<TASK>
usbnet_start_xmit+0x6be/0x2780 drivers/net/usb/usbnet.c:1467
__netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x9a/0x7b0 net/core/dev.c:3606
sch_direct_xmit+0x1ae/0xc30 net/sched/sch_generic.c:343
__dev_xmit_skb net/core/dev.c:3827 [inline]
__dev_queue_xmit+0x13d4/0x43e0 net/core/dev.c:4400
dev_queue_xmit include/linux/netdevice.h:3168 [inline]
neigh_resolve_output net/core/neighbour.c:1514 [inline]
neigh_resolve_output+0x5bc/0x950 net/core/neighbour.c:1494
neigh_output include/net/neighbour.h:539 [inline]
ip6_finish_output2+0xb1b/0x2070 net/ipv6/ip6_output.c:141
__ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
NF_HOOK_COND include/linux/netfilter.h:303 [inline]
ip6_output+0x1f8/0x540 net/ipv6/ip6_output.c:247
dst_output include/net/dst.h:450 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
mld_sendpack+0x9f0/0x11d0 net/ipv6/mcast.c:1819
mld_send_cr net/ipv6/mcast.c:2120 [inline]
mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2651
process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit <d74169ceb0d2> ("iommu/vt-d: Allocate DMAR fault interrupts
locally") moved the call to enable_drhd_fault_handling() to a code
path that does not hold any lock while traversing the drhd list. Fix
it by ensuring the dmar_global_lock lock is held when traversing the
drhd list.
Without this fix, the following warning is triggered:
=============================
WARNING: suspicious RCU usage
6.14.0-rc3 #55 Not tainted
-----------------------------
drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
2 locks held by cpuhp/1/23:
#0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
#1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
stack backtrace:
CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55
Call Trace:
<TASK>
dump_stack_lvl+0xb7/0xd0
lockdep_rcu_suspicious+0x159/0x1f0
? __pfx_enable_drhd_fault_handling+0x10/0x10
enable_drhd_fault_handling+0x151/0x180
cpuhp_invoke_callback+0x1df/0x990
cpuhp_thread_fun+0x1ea/0x2c0
smpboot_thread_fn+0x1f5/0x2e0
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0x12a/0x2d0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x4a/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat
about a possible deadlock between dmar_global_lock and cpu_hotplug_lock.
This is avoided by not holding dmar_global_lock when calling
iommu_device_register(), which initiates the device probe process.
In the Linux kernel, the following vulnerability has been resolved:
dm-integrity: Avoid divide by zero in table status in Inline mode
In Inline mode, the journal is unused, and journal_sectors is zero.
Calculating the journal watermark requires dividing by journal_sectors,
which should be done only if the journal is configured.
Otherwise, a simple table query (dmsetup table) can cause OOPS.
This bug did not show on some systems, perhaps only due to
compiler optimization.
On my 32-bit testing machine, this reliably crashes with the following:
: Oops: divide error: 0000 [#1] PREEMPT SMP
: CPU: 0 UID: 0 PID: 2450 Comm: dmsetup Not tainted 6.14.0-rc2+ #959
: EIP: dm_integrity_status+0x2f8/0xab0 [dm_integrity]
...
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: bsg: Fix crash when arpmb command fails
If the device doesn't support arpmb we'll crash due to copying user data in
bsg_transport_sg_io_fn().
In the case where ufs_bsg_exec_advanced_rpmb_req() returns an error, do not
set the job's reply_len.
Memory crash backtrace:
3,1290,531166405,-;ufshcd 0000:00:12.5: ARPMB OP failed: error code -22
4,1308,531166555,-;Call Trace:
4,1309,531166559,-; <TASK>
4,1310,531166565,-; ? show_regs+0x6d/0x80
4,1311,531166575,-; ? die+0x37/0xa0
4,1312,531166583,-; ? do_trap+0xd4/0xf0
4,1313,531166593,-; ? do_error_trap+0x71/0xb0
4,1314,531166601,-; ? usercopy_abort+0x6c/0x80
4,1315,531166610,-; ? exc_invalid_op+0x52/0x80
4,1316,531166622,-; ? usercopy_abort+0x6c/0x80
4,1317,531166630,-; ? asm_exc_invalid_op+0x1b/0x20
4,1318,531166643,-; ? usercopy_abort+0x6c/0x80
4,1319,531166652,-; __check_heap_object+0xe3/0x120
4,1320,531166661,-; check_heap_object+0x185/0x1d0
4,1321,531166670,-; __check_object_size.part.0+0x72/0x150
4,1322,531166679,-; __check_object_size+0x23/0x30
4,1323,531166688,-; bsg_transport_sg_io_fn+0x314/0x3b0
In the Linux kernel, the following vulnerability has been resolved:
efi: Don't map the entire mokvar table to determine its size
Currently, when validating the mokvar table, we (re)map the entire table
on each iteration of the loop, adding space as we discover new entries.
If the table grows over a certain size, this fails due to limitations of
early_memmap(), and we get a failure and traceback:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:139 __early_ioremap+0xef/0x220
...
Call Trace:
<TASK>
? __early_ioremap+0xef/0x220
? __warn.cold+0x93/0xfa
? __early_ioremap+0xef/0x220
? report_bug+0xff/0x140
? early_fixup_exception+0x5d/0xb0
? early_idt_handler_common+0x2f/0x3a
? __early_ioremap+0xef/0x220
? efi_mokvar_table_init+0xce/0x1d0
? setup_arch+0x864/0xc10
? start_kernel+0x6b/0xa10
? x86_64_start_reservations+0x24/0x30
? x86_64_start_kernel+0xed/0xf0
? common_startup_64+0x13e/0x141
</TASK>
---[ end trace 0000000000000000 ]---
mokvar: Failed to map EFI MOKvar config table pa=0x7c4c3000, size=265187.
Mapping the entire structure isn't actually necessary, as we don't ever
need more than one entry header mapped at once.
Changes efi_mokvar_table_init() to only map each entry header, not the
entire table, when determining the table size. Since we're not mapping
any data past the variable name, it also changes the code to enforce
that each variable name is NUL terminated, rather than attempting to
verify it in place.
In the Linux kernel, the following vulnerability has been resolved:
drm/fbdev-dma: Add shadow buffering for deferred I/O
DMA areas are not necessarily backed by struct page, so we cannot
rely on it for deferred I/O. Allocate a shadow buffer for drivers
that require deferred I/O and use it as framebuffer memory.
Fixes driver errors about being "Unable to handle kernel NULL pointer
dereference at virtual address" or "Unable to handle kernel paging
request at virtual address".
The patch splits drm_fbdev_dma_driver_fbdev_probe() in an initial
allocation, which creates the DMA-backed buffer object, and a tail
that sets up the fbdev data structures. There is a tail function for
direct memory mappings and a tail function for deferred I/O with
the shadow buffer.
It is no longer possible to use deferred I/O without shadow buffer.
It can be re-added if there exists a reliably test for usable struct
page in the allocated DMA-backed buffer object.
In the Linux kernel, the following vulnerability has been resolved:
sched/core: Prevent rescheduling when interrupts are disabled
David reported a warning observed while loop testing kexec jump:
Interrupts enabled after irqrouter_resume+0x0/0x50
WARNING: CPU: 0 PID: 560 at drivers/base/syscore.c:103 syscore_resume+0x18a/0x220
kernel_kexec+0xf6/0x180
__do_sys_reboot+0x206/0x250
do_syscall_64+0x95/0x180
The corresponding interrupt flag trace:
hardirqs last enabled at (15573): [<ffffffffa8281b8e>] __up_console_sem+0x7e/0x90
hardirqs last disabled at (15580): [<ffffffffa8281b73>] __up_console_sem+0x63/0x90
That means __up_console_sem() was invoked with interrupts enabled. Further
instrumentation revealed that in the interrupt disabled section of kexec
jump one of the syscore_suspend() callbacks woke up a task, which set the
NEED_RESCHED flag. A later callback in the resume path invoked
cond_resched() which in turn led to the invocation of the scheduler:
__cond_resched+0x21/0x60
down_timeout+0x18/0x60
acpi_os_wait_semaphore+0x4c/0x80
acpi_ut_acquire_mutex+0x3d/0x100
acpi_ns_get_node+0x27/0x60
acpi_ns_evaluate+0x1cb/0x2d0
acpi_rs_set_srs_method_data+0x156/0x190
acpi_pci_link_set+0x11c/0x290
irqrouter_resume+0x54/0x60
syscore_resume+0x6a/0x200
kernel_kexec+0x145/0x1c0
__do_sys_reboot+0xeb/0x240
do_syscall_64+0x95/0x180
This is a long standing problem, which probably got more visible with
the recent printk changes. Something does a task wakeup and the
scheduler sets the NEED_RESCHED flag. cond_resched() sees it set and
invokes schedule() from a completely bogus context. The scheduler
enables interrupts after context switching, which causes the above
warning at the end.
Quite some of the code paths in syscore_suspend()/resume() can result in
triggering a wakeup with the exactly same consequences. They might not
have done so yet, but as they share a lot of code with normal operations
it's just a question of time.
The problem only affects the PREEMPT_NONE and PREEMPT_VOLUNTARY scheduling
models. Full preemption is not affected as cond_resched() is disabled and
the preemption check preemptible() takes the interrupt disabled flag into
account.
Cure the problem by adding a corresponding check into cond_resched().
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in yudleethemes City Store allows DOM-Based XSS.This issue affects City Store: from n/a through 1.4.5.