In the Linux kernel, the following vulnerability has been resolved:
fs: drop peer group ids under namespace lock
When cleaning up peer group ids in the failure path we need to make sure
to hold on to the namespace lock. Otherwise another thread might just
turn the mount from a shared into a non-shared mount concurrently.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to drop all dirty pages during umount() if cp_error is set
xfstest generic/361 reports a bug as below:
f2fs_bug_on(sbi, sbi->fsync_node_num);
kernel BUG at fs/f2fs/super.c:1627!
RIP: 0010:f2fs_put_super+0x3a8/0x3b0
Call Trace:
generic_shutdown_super+0x8c/0x1b0
kill_block_super+0x2b/0x60
kill_f2fs_super+0x87/0x110
deactivate_locked_super+0x39/0x80
deactivate_super+0x46/0x50
cleanup_mnt+0x109/0x170
__cleanup_mnt+0x16/0x20
task_work_run+0x65/0xa0
exit_to_user_mode_prepare+0x175/0x190
syscall_exit_to_user_mode+0x25/0x50
do_syscall_64+0x4c/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
During umount(), if cp_error is set, f2fs_wait_on_all_pages() should
not stop waiting all F2FS_WB_CP_DATA pages to be writebacked, otherwise,
fsync_node_num can be non-zero after f2fs_wait_on_all_pages() causing
this bug.
In this case, to avoid deadloop in f2fs_wait_on_all_pages(), it needs
to drop all dirty pages rather than redirtying them.
In the Linux kernel, the following vulnerability has been resolved:
md/raid10: fix memleak for 'conf->bio_split'
In the error path of raid10_run(), 'conf' need be freed, however,
'conf->bio_split' is missed and memory will be leaked.
Since there are 3 places to free 'conf', factor out a helper to fix the
problem.
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: Add check for cstate
As kzalloc may fail and return NULL pointer,
it should be better to check cstate
in order to avoid the NULL pointer dereference
in __drm_atomic_helper_crtc_reset.
Patchwork: https://patchwork.freedesktop.org/patch/514163/
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix incorrect splitting in btrfs_drop_extent_map_range
In production we were seeing a variety of WARN_ON()'s in the extent_map
code, specifically in btrfs_drop_extent_map_range() when we have to call
add_extent_mapping() for our second split.
Consider the following extent map layout
PINNED
[0 16K) [32K, 48K)
and then we call btrfs_drop_extent_map_range for [0, 36K), with
skip_pinned == true. The initial loop will have
start = 0
end = 36K
len = 36K
we will find the [0, 16k) extent, but since we are pinned we will skip
it, which has this code
start = em_end;
if (end != (u64)-1)
len = start + len - em_end;
em_end here is 16K, so now the values are
start = 16K
len = 16K + 36K - 16K = 36K
len should instead be 20K. This is a problem when we find the next
extent at [32K, 48K), we need to split this extent to leave [36K, 48k),
however the code for the split looks like this
split->start = start + len;
split->len = em_end - (start + len);
In this case we have
em_end = 48K
split->start = 16K + 36K // this should be 16K + 20K
split->len = 48K - (16K + 36K) // this overflows as 16K + 36K is 52K
and now we have an invalid extent_map in the tree that potentially
overlaps other entries in the extent map. Even in the non-overlapping
case we will have split->start set improperly, which will cause problems
with any block related calculations.
We don't actually need len in this loop, we can simply use end as our
end point, and only adjust start up when we find a pinned extent we need
to skip.
Adjust the logic to do this, which keeps us from inserting an invalid
extent map.
We only skip_pinned in the relocation case, so this is relatively rare,
except in the case where you are running relocation a lot, which can
happen with auto relocation on.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Fix race condition in hidp_session_thread
There is a potential race condition in hidp_session_thread that may
lead to use-after-free. For instance, the timer is active while
hidp_del_timer is called in hidp_session_thread(). After hidp_session_put,
then 'session' will be freed, causing kernel panic when hidp_idle_timeout
is running.
The solution is to use del_timer_sync instead of del_timer.
Here is the call trace:
? hidp_session_probe+0x780/0x780
call_timer_fn+0x2d/0x1e0
__run_timers.part.0+0x569/0x940
hidp_session_probe+0x780/0x780
call_timer_fn+0x1e0/0x1e0
ktime_get+0x5c/0xf0
lapic_next_deadline+0x2c/0x40
clockevents_program_event+0x205/0x320
run_timer_softirq+0xa9/0x1b0
__do_softirq+0x1b9/0x641
__irq_exit_rcu+0xdc/0x190
irq_exit_rcu+0xe/0x20
sysvec_apic_timer_interrupt+0xa1/0xc0
In the Linux kernel, the following vulnerability has been resolved:
inotify: Avoid reporting event with invalid wd
When inotify_freeing_mark() races with inotify_handle_inode_event() it
can happen that inotify_handle_inode_event() sees that i_mark->wd got
already reset to -1 and reports this value to userspace which can
confuse the inotify listener. Avoid the problem by validating that wd is
sensible (and pretend the mark got removed before the event got
generated otherwise).
In the Linux kernel, the following vulnerability has been resolved:
serial: sc16is7xx: setup GPIO controller later in probe
The GPIO controller component of the sc16is7xx driver is setup too
early, which can result in a race condition where another device tries
to utilise the GPIO lines before the sc16is7xx device has finished
initialising.
This issue manifests itself as an Oops when the GPIO lines are configured:
Unable to handle kernel read from unreadable memory at virtual address
...
pc : sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
lr : sc16is7xx_gpio_direction_output+0x4c/0x108 [sc16is7xx]
...
Call trace:
sc16is7xx_gpio_direction_output+0x68/0x108 [sc16is7xx]
gpiod_direction_output_raw_commit+0x64/0x318
gpiod_direction_output+0xb0/0x170
create_gpio_led+0xec/0x198
gpio_led_probe+0x16c/0x4f0
platform_drv_probe+0x5c/0xb0
really_probe+0xe8/0x448
driver_probe_device+0xe8/0x138
__device_attach_driver+0x94/0x118
bus_for_each_drv+0x8c/0xe0
__device_attach+0x100/0x1b8
device_initial_probe+0x28/0x38
bus_probe_device+0xa4/0xb0
deferred_probe_work_func+0x90/0xe0
process_one_work+0x1c4/0x480
worker_thread+0x54/0x430
kthread+0x138/0x150
ret_from_fork+0x10/0x1c
This patch moves the setup of the GPIO controller functions to later in the
probe function, ensuring the sc16is7xx device has already finished
initialising by the time other devices try to make use of the GPIO lines.
The error handling has also been reordered to reflect the new
initialisation order.
In the Linux kernel, the following vulnerability has been resolved:
s390/dcssblk: fix kernel crash with list_add corruption
Commit fb08a1908cb1 ("dax: simplify the dax_device <-> gendisk
association") introduced new logic for gendisk association, requiring
drivers to explicitly call dax_add_host() and dax_remove_host().
For dcssblk driver, some dax_remove_host() calls were missing, e.g. in
device remove path. The commit also broke error handling for out_dax case
in device add path, resulting in an extra put_device() w/o the previous
get_device() in that case.
This lead to stale xarray entries after device add / remove cycles. In the
case when a previously used struct gendisk pointer (xarray index) would be
used again, because blk_alloc_disk() happened to return such a pointer, the
xa_insert() in dax_add_host() would fail and go to out_dax, doing the extra
put_device() in the error path. In combination with an already flawed error
handling in dcssblk (device_register() cleanup), which needs to be
addressed in a separate patch, this resulted in a missing device_del() /
klist_del(), and eventually in the kernel crash with list_add corruption on
a subsequent device_add() / klist_add().
Fix this by adding the missing dax_remove_host() calls, and also move the
put_device() in the error path to restore the previous logic.
In the Linux kernel, the following vulnerability has been resolved:
drm/fbdev-generic: prohibit potential out-of-bounds access
The fbdev test of IGT may write after EOF, which lead to out-of-bound
access for drm drivers with fbdev-generic. For example, run fbdev test
on a x86+ast2400 platform, with 1680x1050 resolution, will cause the
linux kernel hang with the following call trace:
Oops: 0000 [#1] PREEMPT SMP PTI
[IGT] fbdev: starting subtest eof
Workqueue: events drm_fb_helper_damage_work [drm_kms_helper]
[IGT] fbdev: starting subtest nullptr
RIP: 0010:memcpy_erms+0xa/0x20
RSP: 0018:ffffa17d40167d98 EFLAGS: 00010246
RAX: ffffa17d4eb7fa80 RBX: ffffa17d40e0aa80 RCX: 00000000000014c0
RDX: 0000000000001a40 RSI: ffffa17d40e0b000 RDI: ffffa17d4eb80000
RBP: ffffa17d40167e20 R08: 0000000000000000 R09: ffff89522ecff8c0
R10: ffffa17d4e4c5000 R11: 0000000000000000 R12: ffffa17d4eb7fa80
R13: 0000000000001a40 R14: 000000000000041a R15: ffffa17d40167e30
FS: 0000000000000000(0000) GS:ffff895257380000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffa17d40e0b000 CR3: 00000001eaeca006 CR4: 00000000001706e0
Call Trace:
<TASK>
? drm_fbdev_generic_helper_fb_dirty+0x207/0x330 [drm_kms_helper]
drm_fb_helper_damage_work+0x8f/0x170 [drm_kms_helper]
process_one_work+0x21f/0x430
worker_thread+0x4e/0x3c0
? __pfx_worker_thread+0x10/0x10
kthread+0xf4/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2c/0x50
</TASK>
CR2: ffffa17d40e0b000
---[ end trace 0000000000000000 ]---
The is because damage rectangles computed by
drm_fb_helper_memory_range_to_clip() function is not guaranteed to be
bound in the screen's active display area. Possible reasons are:
1) Buffers are allocated in the granularity of page size, for mmap system
call support. The shadow screen buffer consumed by fbdev emulation may
also choosed be page size aligned.
2) The DIV_ROUND_UP() used in drm_fb_helper_memory_range_to_clip()
will introduce off-by-one error.
For example, on a 16KB page size system, in order to store a 1920x1080
XRGB framebuffer, we need allocate 507 pages. Unfortunately, the size
1920*1080*4 can not be divided exactly by 16KB.
1920 * 1080 * 4 = 8294400 bytes
506 * 16 * 1024 = 8290304 bytes
507 * 16 * 1024 = 8306688 bytes
line_length = 1920*4 = 7680 bytes
507 * 16 * 1024 / 7680 = 1081.6
off / line_length = 507 * 16 * 1024 / 7680 = 1081
DIV_ROUND_UP(507 * 16 * 1024, 7680) will yeild 1082
memcpy_toio() typically issue the copy line by line, when copy the last
line, out-of-bound access will be happen. Because:
1082 * line_length = 1082 * 7680 = 8309760, and 8309760 > 8306688
Note that userspace may still write to the invisiable area if a larger
buffer than width x stride is exposed. But it is not a big issue as
long as there still have memory resolve the access if not drafting so
far.
- Also limit the y1 (Daniel)
- keep fix patch it to minimal (Daniel)
- screen_size is page size aligned because of it need mmap (Thomas)
- Adding fixes tag (Thomas)
In the Linux kernel, the following vulnerability has been resolved:
net: nsh: Use correct mac_offset to unwind gso skb in nsh_gso_segment()
As the call trace shows, skb_panic was caused by wrong skb->mac_header
in nsh_gso_segment():
invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 3 PID: 2737 Comm: syz Not tainted 6.3.0-next-20230505 #1
RIP: 0010:skb_panic+0xda/0xe0
call Trace:
skb_push+0x91/0xa0
nsh_gso_segment+0x4f3/0x570
skb_mac_gso_segment+0x19e/0x270
__skb_gso_segment+0x1e8/0x3c0
validate_xmit_skb+0x452/0x890
validate_xmit_skb_list+0x99/0xd0
sch_direct_xmit+0x294/0x7c0
__dev_queue_xmit+0x16f0/0x1d70
packet_xmit+0x185/0x210
packet_snd+0xc15/0x1170
packet_sendmsg+0x7b/0xa0
sock_sendmsg+0x14f/0x160
The root cause is:
nsh_gso_segment() use skb->network_header - nhoff to reset mac_header
in skb_gso_error_unwind() if inner-layer protocol gso fails.
However, skb->network_header may be reset by inner-layer protocol
gso function e.g. mpls_gso_segment. skb->mac_header reset by the
inaccurate network_header will be larger than skb headroom.
nsh_gso_segment
nhoff = skb->network_header - skb->mac_header;
__skb_pull(skb,nsh_len)
skb_mac_gso_segment
mpls_gso_segment
skb_reset_network_header(skb);//skb->network_header+=nsh_len
return -EINVAL;
skb_gso_error_unwind
skb_push(skb, nsh_len);
skb->mac_header = skb->network_header - nhoff;
// skb->mac_header > skb->headroom, cause skb_push panic
Use correct mac_offset to restore mac_header and get rid of nhoff.
In the Linux kernel, the following vulnerability has been resolved:
rcu: dump vmalloc memory info safely
Currently, for double invoke call_rcu(), will dump rcu_head objects memory
info, if the objects is not allocated from the slab allocator, the
vmalloc_dump_obj() will be invoke and the vmap_area_lock spinlock need to
be held, since the call_rcu() can be invoked in interrupt context,
therefore, there is a possibility of spinlock deadlock scenarios.
And in Preempt-RT kernel, the rcutorture test also trigger the following
lockdep warning:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 1
3 locks held by swapper/0/1:
#0: ffffffffb534ee80 (fullstop_mutex){+.+.}-{4:4}, at: torture_init_begin+0x24/0xa0
#1: ffffffffb5307940 (rcu_read_lock){....}-{1:3}, at: rcu_torture_init+0x1ec7/0x2370
#2: ffffffffb536af40 (vmap_area_lock){+.+.}-{3:3}, at: find_vmap_area+0x1f/0x70
irq event stamp: 565512
hardirqs last enabled at (565511): [<ffffffffb379b138>] __call_rcu_common+0x218/0x940
hardirqs last disabled at (565512): [<ffffffffb5804262>] rcu_torture_init+0x20b2/0x2370
softirqs last enabled at (399112): [<ffffffffb36b2586>] __local_bh_enable_ip+0x126/0x170
softirqs last disabled at (399106): [<ffffffffb43fef59>] inet_register_protosw+0x9/0x1d0
Preemption disabled at:
[<ffffffffb58040c3>] rcu_torture_init+0x1f13/0x2370
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.5.0-rc4-rt2-yocto-preempt-rt+ #15
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xb0
dump_stack+0x14/0x20
__might_resched+0x1aa/0x280
? __pfx_rcu_torture_err_cb+0x10/0x10
rt_spin_lock+0x53/0x130
? find_vmap_area+0x1f/0x70
find_vmap_area+0x1f/0x70
vmalloc_dump_obj+0x20/0x60
mem_dump_obj+0x22/0x90
__call_rcu_common+0x5bf/0x940
? debug_smp_processor_id+0x1b/0x30
call_rcu_hurry+0x14/0x20
rcu_torture_init+0x1f82/0x2370
? __pfx_rcu_torture_leak_cb+0x10/0x10
? __pfx_rcu_torture_leak_cb+0x10/0x10
? __pfx_rcu_torture_init+0x10/0x10
do_one_initcall+0x6c/0x300
? debug_smp_processor_id+0x1b/0x30
kernel_init_freeable+0x2b9/0x540
? __pfx_kernel_init+0x10/0x10
kernel_init+0x1f/0x150
ret_from_fork+0x40/0x50
? __pfx_kernel_init+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
The previous patch fixes this by using the deadlock-safe best-effort
version of find_vm_area. However, in case of failure print the fact that
the pointer was a vmalloc pointer so that we print at least something.
In the Linux kernel, the following vulnerability has been resolved:
kcm: Fix memory leak in error path of kcm_sendmsg()
syzbot reported a memory leak like below:
BUG: memory leak
unreferenced object 0xffff88810b088c00 (size 240):
comm "syz-executor186", pid 5012, jiffies 4294943306 (age 13.680s)
hex dump (first 32 bytes):
00 89 08 0b 81 88 ff ff 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff83e5d5ff>] __alloc_skb+0x1ef/0x230 net/core/skbuff.c:634
[<ffffffff84606e59>] alloc_skb include/linux/skbuff.h:1289 [inline]
[<ffffffff84606e59>] kcm_sendmsg+0x269/0x1050 net/kcm/kcmsock.c:815
[<ffffffff83e479c6>] sock_sendmsg_nosec net/socket.c:725 [inline]
[<ffffffff83e479c6>] sock_sendmsg+0x56/0xb0 net/socket.c:748
[<ffffffff83e47f55>] ____sys_sendmsg+0x365/0x470 net/socket.c:2494
[<ffffffff83e4c389>] ___sys_sendmsg+0xc9/0x130 net/socket.c:2548
[<ffffffff83e4c536>] __sys_sendmsg+0xa6/0x120 net/socket.c:2577
[<ffffffff84ad7bb8>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84ad7bb8>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
[<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
In kcm_sendmsg(), kcm_tx_msg(head)->last_skb is used as a cursor to append
newly allocated skbs to 'head'. If some bytes are copied, an error occurred,
and jumped to out_error label, 'last_skb' is left unmodified. A later
kcm_sendmsg() will use an obsoleted 'last_skb' reference, corrupting the
'head' frag_list and causing the leak.
This patch fixes this issue by properly updating the last allocated skb in
'last_skb'.
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: rockchip: Fix refcount leak in rockchip_pinctrl_parse_groups
of_find_node_by_phandle() returns a node pointer with refcount incremented,
We should use of_node_put() on it when not needed anymore.
Add missing of_node_put() to avoid refcount leak.
In the Linux kernel, the following vulnerability has been resolved:
usb: rndis_host: Secure rndis_query check against int overflow
Variables off and len typed as uint32 in rndis_query function
are controlled by incoming RNDIS response message thus their
value may be manipulated. Setting off to a unexpectetly large
value will cause the sum with len and 8 to overflow and pass
the implemented validation step. Consequently the response
pointer will be referring to a location past the expected
buffer boundaries allowing information leakage e.g. via
RNDIS_OID_802_3_PERMANENT_ADDRESS OID.
In the Linux kernel, the following vulnerability has been resolved:
media: rcar_fdp1: Fix refcount leak in probe and remove function
rcar_fcp_get() take reference, which should be balanced with
rcar_fcp_put(). Add missing rcar_fcp_put() in fdp1_remove and
the error paths of fdp1_probe() to fix this.
[hverkuil: resolve merge conflict, remove() is now void]
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Fix DMA-API call trace on NVMe LS requests
The following message and call trace was seen with debug kernels:
DMA-API: qla2xxx 0000:41:00.0: device driver failed to check map
error [device address=0x00000002a3ff38d8] [size=1024 bytes] [mapped as
single]
WARNING: CPU: 0 PID: 2930 at kernel/dma/debug.c:1017
check_unmap+0xf42/0x1990
Call Trace:
debug_dma_unmap_page+0xc9/0x100
qla_nvme_ls_unmap+0x141/0x210 [qla2xxx]
Remove DMA mapping from the driver altogether, as it is already done by FC
layer. This prevents the warning.
In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: dropping parent refcount after pd_free_fn() is done
Some cgroup policies will access parent pd through child pd even
after pd_offline_fn() is done. If pd_free_fn() for parent is called
before child, then UAF can be triggered. Hence it's better to guarantee
the order of pd_free_fn().
Currently refcount of parent blkg is dropped in __blkg_release(), which
is before pd_free_fn() is called in blkg_free_work_fn() while
blkg_free_work_fn() is called asynchronously.
This patch make sure pd_free_fn() called from removing cgroup is ordered
by delaying dropping parent refcount after calling pd_free_fn() for
child.
BTW, pd_free_fn() will also be called from blkcg_deactivate_policy()
from deleting device, and following patches will guarantee the order.
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: fix potential memory leak in mlx5e_init_rep_rx
The memory pointed to by the priv->rx_res pointer is not freed in the error
path of mlx5e_init_rep_rx, which can lead to a memory leak. Fix by freeing
the memory in the error path, thereby making the error path identical to
mlx5e_cleanup_rep_rx().
In the Linux kernel, the following vulnerability has been resolved:
can: isotp: check CAN address family in isotp_bind()
Add missing check to block non-AF_CAN binds.
Syzbot created some code which matched the right sockaddr struct size
but used AF_XDP (0x2C) instead of AF_CAN (0x1D) in the address family
field:
bind$xdp(r2, &(0x7f0000000540)={0x2c, 0x0, r4, 0x0, r2}, 0x10)
^^^^
This has no funtional impact but the userspace should be notified about
the wrong address family field content.
In the Linux kernel, the following vulnerability has been resolved:
mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op()
'op-cs' is copied in 'fun->mchip_number' which is used to access the
'mchip_offsets' and the 'rnb_gpio' arrays.
These arrays have NAND_MAX_CHIPS elements, so the index must be below this
limit.
Fix the sanity check in order to avoid the NAND_MAX_CHIPS value. This
would lead to out-of-bound accesses.
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Prevent lpfc_debugfs_lockstat_write() buffer overflow
A static code analysis tool flagged the possibility of buffer overflow when
using copy_from_user() for a debugfs entry.
Currently, it is possible that copy_from_user() copies more bytes than what
would fit in the mybuf char array. Add a min() restriction check between
sizeof(mybuf) - 1 and nbytes passed from the userspace buffer to protect
against buffer overflow.
In the Linux kernel, the following vulnerability has been resolved:
driver: soc: xilinx: use _safe loop iterator to avoid a use after free
The hash_for_each_possible() loop dereferences "eve_data" to get the
next item on the list. However the loop frees eve_data so it leads to
a use after free. Use hash_for_each_possible_safe() instead.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qedi: Fix use after free bug in qedi_remove()
In qedi_probe() we call __qedi_probe() which initializes
&qedi->recovery_work with qedi_recovery_handler() and
&qedi->board_disable_work with qedi_board_disable_work().
When qedi_schedule_recovery_handler() is called, schedule_delayed_work()
will finally start the work.
In qedi_remove(), which is called to remove the driver, the following
sequence may be observed:
Fix this by finishing the work before cleanup in qedi_remove().
CPU0 CPU1
|qedi_recovery_handler
qedi_remove |
__qedi_remove |
iscsi_host_free |
scsi_host_put |
//free shost |
|iscsi_host_for_each_session
|//use qedi->shost
Cancel recovery_work and board_disable_work in __qedi_remove().
In the Linux kernel, the following vulnerability has been resolved:
fs: Protect reconfiguration of sb read-write from racing writes
The reconfigure / remount code takes a lot of effort to protect
filesystem's reconfiguration code from racing writes on remounting
read-only. However during remounting read-only filesystem to read-write
mode userspace writes can start immediately once we clear SB_RDONLY
flag. This is inconvenient for example for ext4 because we need to do
some writes to the filesystem (such as preparation of quota files)
before we can take userspace writes so we are clearing SB_RDONLY flag
before we are fully ready to accept userpace writes and syzbot has found
a way to exploit this [1]. Also as far as I'm reading the code
the filesystem remount code was protected from racing writes in the
legacy mount path by the mount's MNT_READONLY flag so this is relatively
new problem. It is actually fairly easy to protect remount read-write
from racing writes using sb->s_readonly_remount flag so let's just do
that instead of having to workaround these races in the filesystem code.
[1] https://lore.kernel.org/all/00000000000006a0df05f6667499@google.com/T/
In the Linux kernel, the following vulnerability has been resolved:
regulator: stm32-pwr: fix of_iomap leak
Smatch reports:
drivers/regulator/stm32-pwr.c:166 stm32_pwr_regulator_probe() warn:
'base' from of_iomap() not released on lines: 151,166.
In stm32_pwr_regulator_probe(), base is not released
when devm_kzalloc() fails to allocate memory or
devm_regulator_register() fails to register a new regulator device,
which may cause a leak.
To fix this issue, replace of_iomap() with
devm_platform_ioremap_resource(). devm_platform_ioremap_resource()
is a specialized function for platform devices.
It allows 'base' to be automatically released whether the probe
function succeeds or fails.
Besides, use IS_ERR(base) instead of !base
as the return value of devm_platform_ioremap_resource()
can either be a pointer to the remapped memory or
an ERR_PTR() encoded error code if the operation fails.
In the Linux kernel, the following vulnerability has been resolved:
soundwire: fix enumeration completion
The soundwire subsystem uses two completion structures that allow
drivers to wait for soundwire device to become enumerated on the bus and
initialised by their drivers, respectively.
The code implementing the signalling is currently broken as it does not
signal all current and future waiters and also uses the wrong
reinitialisation function, which can potentially lead to memory
corruption if there are still waiters on the queue.
Not signalling future waiters specifically breaks sound card probe
deferrals as codec drivers can not tell that the soundwire device is
already attached when being reprobed. Some codec runtime PM
implementations suffer from similar problems as waiting for enumeration
during resume can also timeout despite the device already having been
enumerated.
In the Linux kernel, the following vulnerability has been resolved:
powerpc/iommu: Fix notifiers being shared by PCI and VIO buses
fail_iommu_setup() registers the fail_iommu_bus_notifier struct to both
PCI and VIO buses. struct notifier_block is a linked list node, so this
causes any notifiers later registered to either bus type to also be
registered to the other since they share the same node.
This causes issues in (at least) the vgaarb code, which registers a
notifier for PCI buses. pci_notify() ends up being called on a vio
device, converted with to_pci_dev() even though it's not a PCI device,
and finally makes a bad access in vga_arbiter_add_pci_device() as
discovered with KASAN:
BUG: KASAN: slab-out-of-bounds in vga_arbiter_add_pci_device+0x60/0xe00
Read of size 4 at addr c000000264c26fdc by task swapper/0/1
Call Trace:
dump_stack_lvl+0x1bc/0x2b8 (unreliable)
print_report+0x3f4/0xc60
kasan_report+0x244/0x698
__asan_load4+0xe8/0x250
vga_arbiter_add_pci_device+0x60/0xe00
pci_notify+0x88/0x444
notifier_call_chain+0x104/0x320
blocking_notifier_call_chain+0xa0/0x140
device_add+0xac8/0x1d30
device_register+0x58/0x80
vio_register_device_node+0x9ac/0xce0
vio_bus_scan_register_devices+0xc4/0x13c
__machine_initcall_pseries_vio_device_init+0x94/0xf0
do_one_initcall+0x12c/0xaa8
kernel_init_freeable+0xa48/0xba8
kernel_init+0x64/0x400
ret_from_kernel_thread+0x5c/0x64
Fix this by creating separate notifier_block structs for each bus type.
[mpe: Add #ifdef to fix CONFIG_IBMVIO=n build]
In the Linux kernel, the following vulnerability has been resolved:
media: anysee: fix null-ptr-deref in anysee_master_xfer
In anysee_master_xfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach anysee_master_xfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.
Similar commit:
commit 0ed554fd769a
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
[hverkuil: add spaces around +]
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: pv: fix index value of replaced ASCE
The index field of the struct page corresponding to a guest ASCE should
be 0. When replacing the ASCE in s390_replace_asce(), the index of the
new ASCE should also be set to 0.
Having the wrong index might lead to the wrong addresses being passed
around when notifying pte invalidations, and eventually to validity
intercepts (VM crash) if the prefix gets unmapped and the notifier gets
called with the wrong address.
In the Linux kernel, the following vulnerability has been resolved:
drm/client: Fix memory leak in drm_client_target_cloned
dmt_mode is allocated and never freed in this function.
It was found with the ast driver, but most drivers using generic fbdev
setup are probably affected.
This fixes the following kmemleak report:
backtrace:
[<00000000b391296d>] drm_mode_duplicate+0x45/0x220 [drm]
[<00000000e45bb5b3>] drm_client_target_cloned.constprop.0+0x27b/0x480 [drm]
[<00000000ed2d3a37>] drm_client_modeset_probe+0x6bd/0xf50 [drm]
[<0000000010e5cc9d>] __drm_fb_helper_initial_config_and_unlock+0xb4/0x2c0 [drm_kms_helper]
[<00000000909f82ca>] drm_fbdev_client_hotplug+0x2bc/0x4d0 [drm_kms_helper]
[<00000000063a69aa>] drm_client_register+0x169/0x240 [drm]
[<00000000a8c61525>] ast_pci_probe+0x142/0x190 [ast]
[<00000000987f19bb>] local_pci_probe+0xdc/0x180
[<000000004fca231b>] work_for_cpu_fn+0x4e/0xa0
[<0000000000b85301>] process_one_work+0x8b7/0x1540
[<000000003375b17c>] worker_thread+0x70a/0xed0
[<00000000b0d43cd9>] kthread+0x29f/0x340
[<000000008d770833>] ret_from_fork+0x1f/0x30
unreferenced object 0xff11000333089a00 (size 128):
In the Linux kernel, the following vulnerability has been resolved:
ixgbe: Fix panic during XDP_TX with > 64 CPUs
Commit 4fe815850bdc ("ixgbe: let the xdpdrv work with more than 64 cpus")
adds support to allow XDP programs to run on systems with more than
64 CPUs by locking the XDP TX rings and indexing them using cpu % 64
(IXGBE_MAX_XDP_QS).
Upon trying this out patch on a system with more than 64 cores,
the kernel paniced with an array-index-out-of-bounds at the return in
ixgbe_determine_xdp_ring in ixgbe.h, which means ixgbe_determine_xdp_q_idx
was just returning the cpu instead of cpu % IXGBE_MAX_XDP_QS. An example
splat:
==========================================================================
UBSAN: array-index-out-of-bounds in
/var/lib/dkms/ixgbe/5.18.6+focal-1/build/src/ixgbe.h:1147:26
index 65 is out of range for type 'ixgbe_ring *[64]'
==========================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000058
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 65 PID: 408 Comm: ksoftirqd/65
Tainted: G IOE 5.15.0-48-generic #54~20.04.1-Ubuntu
Hardware name: Dell Inc. PowerEdge R640/0W23H8, BIOS 2.5.4 01/13/2020
RIP: 0010:ixgbe_xmit_xdp_ring+0x1b/0x1c0 [ixgbe]
Code: 3b 52 d4 cf e9 42 f2 ff ff 66 0f 1f 44 00 00 0f 1f 44 00 00 55 b9
00 00 00 00 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 08 <44> 0f b7
47 58 0f b7 47 5a 0f b7 57 54 44 0f b7 76 08 66 41 39 c0
RSP: 0018:ffffbc3fcd88fcb0 EFLAGS: 00010282
RAX: ffff92a253260980 RBX: ffffbc3fe68b00a0 RCX: 0000000000000000
RDX: ffff928b5f659000 RSI: ffff928b5f659000 RDI: 0000000000000000
RBP: ffffbc3fcd88fce0 R08: ffff92b9dfc20580 R09: 0000000000000001
R10: 3d3d3d3d3d3d3d3d R11: 3d3d3d3d3d3d3d3d R12: 0000000000000000
R13: ffff928b2f0fa8c0 R14: ffff928b9be20050 R15: 000000000000003c
FS: 0000000000000000(0000) GS:ffff92b9dfc00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000058 CR3: 000000011dd6a002 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
ixgbe_poll+0x103e/0x1280 [ixgbe]
? sched_clock_cpu+0x12/0xe0
__napi_poll+0x30/0x160
net_rx_action+0x11c/0x270
__do_softirq+0xda/0x2ee
run_ksoftirqd+0x2f/0x50
smpboot_thread_fn+0xb7/0x150
? sort_range+0x30/0x30
kthread+0x127/0x150
? set_kthread_struct+0x50/0x50
ret_from_fork+0x1f/0x30
</TASK>
I think this is how it happens:
Upon loading the first XDP program on a system with more than 64 CPUs,
ixgbe_xdp_locking_key is incremented in ixgbe_xdp_setup. However,
immediately after this, the rings are reconfigured by ixgbe_setup_tc.
ixgbe_setup_tc calls ixgbe_clear_interrupt_scheme which calls
ixgbe_free_q_vectors which calls ixgbe_free_q_vector in a loop.
ixgbe_free_q_vector decrements ixgbe_xdp_locking_key once per call if
it is non-zero. Commenting out the decrement in ixgbe_free_q_vector
stopped my system from panicing.
I suspect to make the original patch work, I would need to load an XDP
program and then replace it in order to get ixgbe_xdp_locking_key back
above 0 since ixgbe_setup_tc is only called when transitioning between
XDP and non-XDP ring configurations, while ixgbe_xdp_locking_key is
incremented every time ixgbe_xdp_setup is called.
Also, ixgbe_setup_tc can be called via ethtool --set-channels, so this
becomes another path to decrement ixgbe_xdp_locking_key to 0 on systems
with more than 64 CPUs.
Since ixgbe_xdp_locking_key only protects the XDP_TX path and is tied
to the number of CPUs present, there is no reason to disable it upon
unloading an XDP program. To avoid confusion, I have moved enabling
ixgbe_xdp_locking_key into ixgbe_sw_init, which is part of the probe path.
In the Linux kernel, the following vulnerability has been resolved:
virtio_pmem: add the missing REQ_OP_WRITE for flush bio
When doing mkfs.xfs on a pmem device, the following warning was
------------[ cut here ]------------
WARNING: CPU: 2 PID: 384 at block/blk-core.c:751 submit_bio_noacct
Modules linked in:
CPU: 2 PID: 384 Comm: mkfs.xfs Not tainted 6.4.0-rc7+ #154
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:submit_bio_noacct+0x340/0x520
......
Call Trace:
<TASK>
? submit_bio_noacct+0xd5/0x520
submit_bio+0x37/0x60
async_pmem_flush+0x79/0xa0
nvdimm_flush+0x17/0x40
pmem_submit_bio+0x370/0x390
__submit_bio+0xbc/0x190
submit_bio_noacct_nocheck+0x14d/0x370
submit_bio_noacct+0x1ef/0x520
submit_bio+0x55/0x60
submit_bio_wait+0x5a/0xc0
blkdev_issue_flush+0x44/0x60
The root cause is that submit_bio_noacct() needs bio_op() is either
WRITE or ZONE_APPEND for flush bio and async_pmem_flush() doesn't assign
REQ_OP_WRITE when allocating flush bio, so submit_bio_noacct just fail
the flush bio.
Simply fix it by adding the missing REQ_OP_WRITE for flush bio. And we
could fix the flush order issue and do flush optimization later.
In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: hold queue_lock when removing blkg->q_node
When blkg is removed from q->blkg_list from blkg_free_workfn(), queue_lock
has to be held, otherwise, all kinds of bugs(list corruption, hard lockup,
..) can be triggered from blkg_destroy_all().
In the Linux kernel, the following vulnerability has been resolved:
ubi: Fix possible null-ptr-deref in ubi_free_volume()
It willl cause null-ptr-deref in the following case:
uif_init()
ubi_add_volume()
cdev_add() -> if it fails, call kill_volumes()
device_register()
kill_volumes() -> if ubi_add_volume() fails call this function
ubi_free_volume()
cdev_del()
device_unregister() -> trying to delete a not added device,
it causes null-ptr-deref
So in ubi_free_volume(), it delete devices whether they are added
or not, it will causes null-ptr-deref.
Handle the error case whlie calling ubi_add_volume() to fix this
problem. If add volume fails, set the corresponding vol to null,
so it can not be accessed in kill_volumes() and release the
resource in ubi_add_volume() error path.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Add preempt_count_{sub,add} into btf id deny list
The recursion check in __bpf_prog_enter* and __bpf_prog_exit*
leave preempt_count_{sub,add} unprotected. When attaching trampoline to
them we get panic as follows,
[ 867.843050] BUG: TASK stack guard page was hit at 0000000009d325cf (stack is 0000000046a46a15..00000000537e7b28)
[ 867.843064] stack guard page: 0000 [#1] PREEMPT SMP NOPTI
[ 867.843067] CPU: 8 PID: 11009 Comm: trace Kdump: loaded Not tainted 6.2.0+ #4
[ 867.843100] Call Trace:
[ 867.843101] <TASK>
[ 867.843104] asm_exc_int3+0x3a/0x40
[ 867.843108] RIP: 0010:preempt_count_sub+0x1/0xa0
[ 867.843135] __bpf_prog_enter_recur+0x17/0x90
[ 867.843148] bpf_trampoline_6442468108_0+0x2e/0x1000
[ 867.843154] ? preempt_count_sub+0x1/0xa0
[ 867.843157] preempt_count_sub+0x5/0xa0
[ 867.843159] ? migrate_enable+0xac/0xf0
[ 867.843164] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843168] bpf_trampoline_6442468108_0+0x55/0x1000
...
[ 867.843788] preempt_count_sub+0x5/0xa0
[ 867.843793] ? migrate_enable+0xac/0xf0
[ 867.843829] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843837] BUG: IRQ stack guard page was hit at 0000000099bd8228 (stack is 00000000b23e2bc4..000000006d95af35)
[ 867.843841] BUG: IRQ stack guard page was hit at 000000005ae07924 (stack is 00000000ffd69623..0000000014eb594c)
[ 867.843843] BUG: IRQ stack guard page was hit at 00000000028320f0 (stack is 00000000034b6438..0000000078d1bcec)
[ 867.843842] bpf_trampoline_6442468108_0+0x55/0x1000
...
That is because in __bpf_prog_exit_recur, the preempt_count_{sub,add} are
called after prog->active is decreased.
Fixing this by adding these two functions into btf ids deny list.
In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix NULL pointer dereference on fastopen early fallback
In case of early fallback to TCP, subflow_syn_recv_sock() deletes
the subflow context before returning the newly allocated sock to
the caller.
The fastopen path does not cope with the above unconditionally
dereferencing the subflow context.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: firewire-digi00x: prevent potential use after free
This code was supposed to return an error code if init_stream()
failed, but it instead freed dg00x->rx_stream and returned success.
This potentially leads to a use after free.
In the Linux kernel, the following vulnerability has been resolved:
phy: tegra: xusb: Clear the driver reference in usb-phy dev
For the dual-role port, it will assign the phy dev to usb-phy dev and
use the port dev driver as the dev driver of usb-phy.
When we try to destroy the port dev, it will destroy its dev driver
as well. But we did not remove the reference from usb-phy dev. This
might cause the use-after-free issue in KASAN.
In the Linux kernel, the following vulnerability has been resolved:
xen: speed up grant-table reclaim
When a grant entry is still in use by the remote domain, Linux must put
it on a deferred list. Normally, this list is very short, because
the PV network and block protocols expect the backend to unmap the grant
first. However, Qubes OS's GUI protocol is subject to the constraints
of the X Window System, and as such winds up with the frontend unmapping
the window first. As a result, the list can grow very large, resulting
in a massive memory leak and eventual VM freeze.
To partially solve this problem, make the number of entries that the VM
will attempt to free at each iteration tunable. The default is still
10, but it can be overridden via a module parameter.
This is Cc: stable because (when combined with appropriate userspace
changes) it fixes a severe performance and stability problem for Qubes
OS users.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: zoned: skip splitting and logical rewriting on pre-alloc write
When doing a relocation, there is a chance that at the time of
btrfs_reloc_clone_csums(), there is no checksum for the corresponding
region.
In this case, btrfs_finish_ordered_zoned()'s sum points to an invalid item
and so ordered_extent's logical is set to some invalid value. Then,
btrfs_lookup_block_group() in btrfs_zone_finish_endio() failed to find a
block group and will hit an assert or a null pointer dereference as
following.
This can be reprodcued by running btrfs/028 several times (e.g, 4 to 16
times) with a null_blk setup. The device's zone size and capacity is set to
32 MB and the storage size is set to 5 GB on my setup.
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
CPU: 6 PID: 3105720 Comm: kworker/u16:13 Tainted: G W 6.5.0-rc6-kts+ #1
Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0 12/17/2015
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
Code: 41 54 49 89 fc 55 48 89 f5 53 e8 57 7d fc ff 48 8d b8 88 00 00 00 48 89 c3 48 b8 00 00 00 00 00
> 3c 02 00 0f 85 02 01 00 00 f6 83 88 00 00 00 01 0f 84 a8 00 00
RSP: 0018:ffff88833cf87b08 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088
RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed102877b827
R10: ffff888143bdc13b R11: ffff888125b1cbc0 R12: ffff888143bdc000
R13: 0000000000007000 R14: ffff888125b1cba8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88881e500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ed85223d5 CR3: 00000001519b4005 CR4: 00000000001706e0
Call Trace:
<TASK>
? die_addr+0x3c/0xa0
? exc_general_protection+0x148/0x220
? asm_exc_general_protection+0x22/0x30
? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
? btrfs_zone_finish_endio.part.0+0x19/0x160 [btrfs]
btrfs_finish_one_ordered+0x7b8/0x1de0 [btrfs]
? rcu_is_watching+0x11/0xb0
? lock_release+0x47a/0x620
? btrfs_finish_ordered_zoned+0x59b/0x800 [btrfs]
? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs]
? btrfs_finish_ordered_zoned+0x358/0x800 [btrfs]
? __smp_call_single_queue+0x124/0x350
? rcu_is_watching+0x11/0xb0
btrfs_work_helper+0x19f/0xc60 [btrfs]
? __pfx_try_to_wake_up+0x10/0x10
? _raw_spin_unlock_irq+0x24/0x50
? rcu_is_watching+0x11/0xb0
process_one_work+0x8c1/0x1430
? __pfx_lock_acquire+0x10/0x10
? __pfx_process_one_work+0x10/0x10
? __pfx_do_raw_spin_lock+0x10/0x10
? _raw_spin_lock_irq+0x52/0x60
worker_thread+0x100/0x12c0
? __kthread_parkme+0xc1/0x1f0
? __pfx_worker_thread+0x10/0x10
kthread+0x2ea/0x3c0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
On the zoned mode, writing to pre-allocated region means data relocation
write. Such write always uses WRITE command so there is no need of splitting
and rewriting logical address. Thus, we can just skip the function for the
case.
In the Linux kernel, the following vulnerability has been resolved:
power: supply: bq27xxx: Fix poll_interval handling and races on remove
Before this patch bq27xxx_battery_teardown() was setting poll_interval = 0
to avoid bq27xxx_battery_update() requeuing the delayed_work item.
There are 2 problems with this:
1. If the driver is unbound through sysfs, rather then the module being
rmmod-ed, this changes poll_interval unexpectedly
2. This is racy, after it being set poll_interval could be changed
before bq27xxx_battery_update() checks it through
/sys/module/bq27xxx_battery/parameters/poll_interval
Fix this by added a removed attribute to struct bq27xxx_device_info and
using that instead of setting poll_interval to 0.
There also is another poll_interval related race on remove(), writing
/sys/module/bq27xxx_battery/parameters/poll_interval will requeue
the delayed_work item for all devices on the bq27xxx_battery_devices
list and the device being removed was only removed from that list
after cancelling the delayed_work item.
Fix this by moving the removal from the bq27xxx_battery_devices list
to before cancelling the delayed_work item.