| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Fix hard lockup when reading the rx_monitor from debugfs
During I/O and simultaneous cat of /sys/kernel/debug/lpfc/fnX/rx_monitor, a
hard lockup similar to the call trace below may occur.
The spin_lock_bh in lpfc_rx_monitor_report is not protecting from timer
interrupts as expected, so change the strength of the spin lock to _irq.
Kernel panic - not syncing: Hard LOCKUP
CPU: 3 PID: 110402 Comm: cat Kdump: loaded
exception RIP: native_queued_spin_lock_slowpath+91
[IRQ stack]
native_queued_spin_lock_slowpath at ffffffffb814e30b
_raw_spin_lock at ffffffffb89a667a
lpfc_rx_monitor_record at ffffffffc0a73a36 [lpfc]
lpfc_cmf_timer at ffffffffc0abbc67 [lpfc]
__hrtimer_run_queues at ffffffffb8184250
hrtimer_interrupt at ffffffffb8184ab0
smp_apic_timer_interrupt at ffffffffb8a026ba
apic_timer_interrupt at ffffffffb8a01c4f
[End of IRQ stack]
apic_timer_interrupt at ffffffffb8a01c4f
lpfc_rx_monitor_report at ffffffffc0a73c80 [lpfc]
lpfc_rx_monitor_read at ffffffffc0addde1 [lpfc]
full_proxy_read at ffffffffb83e7fc3
vfs_read at ffffffffb833fe71
ksys_read at ffffffffb83402af
do_syscall_64 at ffffffffb800430b
entry_SYSCALL_64_after_hwframe at ffffffffb8a000ad |
| In the Linux kernel, the following vulnerability has been resolved:
erofs: validate the extent length for uncompressed pclusters
syzkaller reported a KASAN use-after-free:
https://syzkaller.appspot.com/bug?extid=2ae90e873e97f1faf6f2
The referenced fuzzed image actually has two issues:
- m_pa == 0 as a non-inlined pcluster;
- The logical length is longer than its physical length.
The first issue has already been addressed. This patch addresses
the second issue by checking the extent length validity. |
| In the Linux kernel, the following vulnerability has been resolved:
iommufd: Do not add the same hwpt to the ioas->hwpt_list twice
The hwpt is added to the hwpt_list only during its creation, it is never
added again. This hunk is some missed leftover from rework. Adding it
twice will corrupt the linked list in some cases.
It effects HWPT specific attachment, which is something the test suite
cannot cover until we can create a legitimate struct device with a
non-system iommu "driver" (ie we need the bus removed from the iommu code) |
| In the Linux kernel, the following vulnerability has been resolved:
virtio-crypto: fix memory leak in virtio_crypto_alg_skcipher_close_session()
'vc_ctrl_req' is alloced in virtio_crypto_alg_skcipher_close_session(),
and should be freed in the invalid ctrl_status->status error handling
case. Otherwise there is a memory leak. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: fix potential memory leak in wilc_mac_xmit()
The wilc_mac_xmit() returns NETDEV_TX_OK without freeing skb, add
dev_kfree_skb() to fix it. Compile tested only. |
| In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix XDP_TX path
For XDP_TX action in bnxt_rx_xdp(), clearing of the event flags is not
correct. __bnxt_poll_work() -> bnxt_rx_pkt() -> bnxt_rx_xdp() may be
looping within NAPI and some event flags may be set in earlier
iterations. In particular, if BNXT_TX_EVENT is set earlier indicating
some XDP_TX packets are ready and pending, it will be cleared if it is
XDP_TX action again. Normally, we will set BNXT_TX_EVENT again when we
successfully call __bnxt_xmit_xdp(). But if the TX ring has no more
room, the flag will not be set. This will cause the TX producer to be
ahead but the driver will not hit the TX doorbell.
For multi-buf XDP_TX, there is no need to clear the event flags and set
BNXT_AGG_EVENT. The BNXT_AGG_EVENT flag should have been set earlier in
bnxt_rx_pkt().
The visible symptom of this is that the RX ring associated with the
TX XDP ring will eventually become empty and all packets will be dropped.
Because this condition will cause the driver to not refill the RX ring
seeing that the TX ring has forever pending XDP_TX packets.
The fix is to only clear BNXT_RX_EVENT when we have successfully
called __bnxt_xmit_xdp(). |
| In the Linux kernel, the following vulnerability has been resolved:
HSI: ssi_protocol: fix potential resource leak in ssip_pn_open()
ssip_pn_open() claims the HSI client's port with hsi_claim_port(). When
hsi_register_port_event() gets some error and returns a negetive value,
the HSI client's port should be released with hsi_release_port().
Fix it by calling hsi_release_port() when hsi_register_port_event() fails. |
| In the Linux kernel, the following vulnerability has been resolved:
md: fix warning for holder mismatch from export_rdev()
Commit a1d767191096 ("md: use mddev->external to select holder in
export_rdev()") fix the problem that 'claim_rdev' is used for
blkdev_get_by_dev() while 'rdev' is used for blkdev_put().
However, if mddev->external is changed from 0 to 1, then 'rdev' is used
for blkdev_get_by_dev() while 'claim_rdev' is used for blkdev_put(). And
this problem can be reporduced reliably by following:
New file: mdadm/tests/23rdev-lifetime
devname=${dev0##*/}
devt=`cat /sys/block/$devname/dev`
pid=""
runtime=2
clean_up_test() {
pill -9 $pid
echo clear > /sys/block/md0/md/array_state
}
trap 'clean_up_test' EXIT
add_by_sysfs() {
while true; do
echo $devt > /sys/block/md0/md/new_dev
done
}
remove_by_sysfs(){
while true; do
echo remove > /sys/block/md0/md/dev-${devname}/state
done
}
echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed"
add_by_sysfs &
pid="$pid $!"
remove_by_sysfs &
pid="$pid $!"
sleep $runtime
exit 0
Test cmd:
./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime
Test result:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 960 at block/bdev.c:618 blkdev_put+0x27c/0x330
Modules linked in: multipath md_mod loop
CPU: 0 PID: 960 Comm: test Not tainted 6.5.0-rc2-00121-g01e55c376936-dirty #50
RIP: 0010:blkdev_put+0x27c/0x330
Call Trace:
<TASK>
export_rdev.isra.23+0x50/0xa0 [md_mod]
mddev_unlock+0x19d/0x300 [md_mod]
rdev_attr_store+0xec/0x190 [md_mod]
sysfs_kf_write+0x52/0x70
kernfs_fop_write_iter+0x19a/0x2a0
vfs_write+0x3b5/0x770
ksys_write+0x74/0x150
__x64_sys_write+0x22/0x30
do_syscall_64+0x40/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fix the problem by recording if 'rdev' is used as holder. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: wavefront: Fix integer overflow in sample size validation
The wavefront_send_sample() function has an integer overflow issue
when validating sample size. The header->size field is u32 but gets
cast to int for comparison with dev->freemem
Fix by using unsigned comparison to avoid integer overflow. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid1: stop mdx_raid1 thread when raid1 array run failed
fail run raid1 array when we assemble array with the inactive disk only,
but the mdx_raid1 thread were not stop, Even if the associated resources
have been released. it will caused a NULL dereference when we do poweroff.
This causes the following Oops:
[ 287.587787] BUG: kernel NULL pointer dereference, address: 0000000000000070
[ 287.594762] #PF: supervisor read access in kernel mode
[ 287.599912] #PF: error_code(0x0000) - not-present page
[ 287.605061] PGD 0 P4D 0
[ 287.607612] Oops: 0000 [#1] SMP NOPTI
[ 287.611287] CPU: 3 PID: 5265 Comm: md0_raid1 Tainted: G U 5.10.146 #0
[ 287.619029] Hardware name: xxxxxxx/To be filled by O.E.M, BIOS 5.19 06/16/2022
[ 287.626775] RIP: 0010:md_check_recovery+0x57/0x500 [md_mod]
[ 287.632357] Code: fe 01 00 00 48 83 bb 10 03 00 00 00 74 08 48 89 ......
[ 287.651118] RSP: 0018:ffffc90000433d78 EFLAGS: 00010202
[ 287.656347] RAX: 0000000000000000 RBX: ffff888105986800 RCX: 0000000000000000
[ 287.663491] RDX: ffffc90000433bb0 RSI: 00000000ffffefff RDI: ffff888105986800
[ 287.670634] RBP: ffffc90000433da0 R08: 0000000000000000 R09: c0000000ffffefff
[ 287.677771] R10: 0000000000000001 R11: ffffc90000433ba8 R12: ffff888105986800
[ 287.684907] R13: 0000000000000000 R14: fffffffffffffe00 R15: ffff888100b6b500
[ 287.692052] FS: 0000000000000000(0000) GS:ffff888277f80000(0000) knlGS:0000000000000000
[ 287.700149] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 287.705897] CR2: 0000000000000070 CR3: 000000000320a000 CR4: 0000000000350ee0
[ 287.713033] Call Trace:
[ 287.715498] raid1d+0x6c/0xbbb [raid1]
[ 287.719256] ? __schedule+0x1ff/0x760
[ 287.722930] ? schedule+0x3b/0xb0
[ 287.726260] ? schedule_timeout+0x1ed/0x290
[ 287.730456] ? __switch_to+0x11f/0x400
[ 287.734219] md_thread+0xe9/0x140 [md_mod]
[ 287.738328] ? md_thread+0xe9/0x140 [md_mod]
[ 287.742601] ? wait_woken+0x80/0x80
[ 287.746097] ? md_register_thread+0xe0/0xe0 [md_mod]
[ 287.751064] kthread+0x11a/0x140
[ 287.754300] ? kthread_park+0x90/0x90
[ 287.757974] ret_from_fork+0x1f/0x30
In fact, when raid1 array run fail, we need to do
md_unregister_thread() before raid1_free(). |
| In the Linux kernel, the following vulnerability has been resolved:
ice: set tx_tstamps when creating new Tx rings via ethtool
When the user changes the number of queues via ethtool, the driver
allocates new rings. This allocation did not initialize tx_tstamps. This
results in the tx_tstamps field being zero (due to kcalloc allocation), and
would result in a NULL pointer dereference when attempting a transmit
timestamp on the new ring. |
| In the Linux kernel, the following vulnerability has been resolved:
dm clone: Fix UAF in clone_dtr()
Dm_clone also has the same UAF problem when dm_resume()
and dm_destroy() are concurrent.
Therefore, cancelling timer again in clone_dtr(). |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: disable sdma ecc irq only when sdma RAS is enabled in suspend
sdma_v4_0_ip is shared on a few asics, but in sdma_v4_0_hw_fini,
driver unconditionally disables ecc_irq which is only enabled on
those asics enabling sdma ecc. This will introduce a warning in
suspend cycle on those chips with sdma ip v4.0, while without
sdma ecc. So this patch correct this.
[ 7283.166354] RIP: 0010:amdgpu_irq_put+0x45/0x70 [amdgpu]
[ 7283.167001] RSP: 0018:ffff9a5fc3967d08 EFLAGS: 00010246
[ 7283.167019] RAX: ffff98d88afd3770 RBX: 0000000000000001 RCX: 0000000000000000
[ 7283.167023] RDX: 0000000000000000 RSI: ffff98d89da30390 RDI: ffff98d89da20000
[ 7283.167025] RBP: ffff98d89da20000 R08: 0000000000036838 R09: 0000000000000006
[ 7283.167028] R10: ffffd5764243c008 R11: 0000000000000000 R12: ffff98d89da30390
[ 7283.167030] R13: ffff98d89da38978 R14: ffffffff999ae15a R15: ffff98d880130105
[ 7283.167032] FS: 0000000000000000(0000) GS:ffff98d996f00000(0000) knlGS:0000000000000000
[ 7283.167036] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7283.167039] CR2: 00000000f7a9d178 CR3: 00000001c42ea000 CR4: 00000000003506e0
[ 7283.167041] Call Trace:
[ 7283.167046] <TASK>
[ 7283.167048] sdma_v4_0_hw_fini+0x38/0xa0 [amdgpu]
[ 7283.167704] amdgpu_device_ip_suspend_phase2+0x101/0x1a0 [amdgpu]
[ 7283.168296] amdgpu_device_suspend+0x103/0x180 [amdgpu]
[ 7283.168875] amdgpu_pmops_freeze+0x21/0x60 [amdgpu]
[ 7283.169464] pci_pm_freeze+0x54/0xc0 |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: mediatek: common: Fix refcount leak in parse_dai_link_info
Add missing of_node_put()s before the returns to balance
of_node_get()s and of_node_put()s, which may get unbalanced
in case the for loop 'for_each_available_child_of_node' returns
early. |
| 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:
media: vidtv: Fix use-after-free in vidtv_bridge_dvb_init()
KASAN reports a use-after-free:
BUG: KASAN: use-after-free in dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core]
Call Trace:
...
dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core]
vidtv_bridge_probe+0x7bf/0xa40 [dvb_vidtv_bridge]
platform_probe+0xb6/0x170
...
Allocated by task 1238:
...
dvb_register_device+0x1a7/0xa70 [dvb_core]
dvb_dmxdev_init+0x2af/0x4a0 [dvb_core]
vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge]
...
Freed by task 1238:
dvb_register_device+0x6d2/0xa70 [dvb_core]
dvb_dmxdev_init+0x2af/0x4a0 [dvb_core]
vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge]
...
It is because the error handling in vidtv_bridge_dvb_init() is wrong.
First, vidtv_bridge_dmx(dev)_init() will clean themselves when fail, but
goto fail_dmx(_dev): calls release functions again, which causes
use-after-free.
Also, in fail_fe, fail_tuner_probe and fail_demod_probe, j = i will cause
out-of-bound when i finished its loop (i == NUM_FE). And the loop
releasing is wrong, although now NUM_FE is 1 so it won't cause problem.
Fix this by correctly releasing everything. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix kernel BUG in ocfs2_find_victim_chain
syzbot reported a kernel BUG in ocfs2_find_victim_chain() because the
`cl_next_free_rec` field of the allocation chain list (next free slot in
the chain list) is 0, triggring the BUG_ON(!cl->cl_next_free_rec)
condition in ocfs2_find_victim_chain() and panicking the kernel.
To fix this, an if condition is introduced in ocfs2_claim_suballoc_bits(),
just before calling ocfs2_find_victim_chain(), the code block in it being
executed when either of the following conditions is true:
1. `cl_next_free_rec` is equal to 0, indicating that there are no free
chains in the allocation chain list
2. `cl_next_free_rec` is greater than `cl_count` (the total number of
chains in the allocation chain list)
Either of them being true is indicative of the fact that there are no
chains left for usage.
This is addressed using ocfs2_error(), which prints
the error log for debugging purposes, rather than panicking the kernel. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/apic: Don't disable x2APIC if locked
The APIC supports two modes, legacy APIC (or xAPIC), and Extended APIC
(or x2APIC). X2APIC mode is mostly compatible with legacy APIC, but
it disables the memory-mapped APIC interface in favor of one that uses
MSRs. The APIC mode is controlled by the EXT bit in the APIC MSR.
The MMIO/xAPIC interface has some problems, most notably the APIC LEAK
[1]. This bug allows an attacker to use the APIC MMIO interface to
extract data from the SGX enclave.
Introduce support for a new feature that will allow the BIOS to lock
the APIC in x2APIC mode. If the APIC is locked in x2APIC mode and the
kernel tries to disable the APIC or revert to legacy APIC mode a GP
fault will occur.
Introduce support for a new MSR (IA32_XAPIC_DISABLE_STATUS) and handle
the new locked mode when the LEGACY_XAPIC_DISABLED bit is set by
preventing the kernel from trying to disable the x2APIC.
On platforms with the IA32_XAPIC_DISABLE_STATUS MSR, if SGX or TDX are
enabled the LEGACY_XAPIC_DISABLED will be set by the BIOS. If
legacy APIC is required, then it SGX and TDX need to be disabled in the
BIOS.
[1]: https://aepicleak.com/aepicleak.pdf |
| In the Linux kernel, the following vulnerability has been resolved:
net: core: remove unnecessary frame_sz check in bpf_xdp_adjust_tail()
Syzkaller reported the following issue:
=======================================
Too BIG xdp->frame_sz = 131072
WARNING: CPU: 0 PID: 5020 at net/core/filter.c:4121
____bpf_xdp_adjust_tail net/core/filter.c:4121 [inline]
WARNING: CPU: 0 PID: 5020 at net/core/filter.c:4121
bpf_xdp_adjust_tail+0x466/0xa10 net/core/filter.c:4103
...
Call Trace:
<TASK>
bpf_prog_4add87e5301a4105+0x1a/0x1c
__bpf_prog_run include/linux/filter.h:600 [inline]
bpf_prog_run_xdp include/linux/filter.h:775 [inline]
bpf_prog_run_generic_xdp+0x57e/0x11e0 net/core/dev.c:4721
netif_receive_generic_xdp net/core/dev.c:4807 [inline]
do_xdp_generic+0x35c/0x770 net/core/dev.c:4866
tun_get_user+0x2340/0x3ca0 drivers/net/tun.c:1919
tun_chr_write_iter+0xe8/0x210 drivers/net/tun.c:2043
call_write_iter include/linux/fs.h:1871 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x650/0xe40 fs/read_write.c:584
ksys_write+0x12f/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
xdp->frame_sz > PAGE_SIZE check was introduced in commit c8741e2bfe87
("xdp: Allow bpf_xdp_adjust_tail() to grow packet size"). But Jesper
Dangaard Brouer <jbrouer@redhat.com> noted that after introducing the
xdp_init_buff() which all XDP driver use - it's safe to remove this
check. The original intend was to catch cases where XDP drivers have
not been updated to use xdp.frame_sz, but that is not longer a concern
(since xdp_init_buff).
Running the initial syzkaller repro it was discovered that the
contiguous physical memory allocation is used for both xdp paths in
tun_get_user(), e.g. tun_build_skb() and tun_alloc_skb(). It was also
stated by Jesper Dangaard Brouer <jbrouer@redhat.com> that XDP can
work on higher order pages, as long as this is contiguous physical
memory (e.g. a page). |
| In the Linux kernel, the following vulnerability has been resolved:
zsmalloc: move LRU update from zs_map_object() to zs_malloc()
Under memory pressure, we sometimes observe the following crash:
[ 5694.832838] ------------[ cut here ]------------
[ 5694.842093] list_del corruption, ffff888014b6a448->next is LIST_POISON1 (dead000000000100)
[ 5694.858677] WARNING: CPU: 33 PID: 418824 at lib/list_debug.c:47 __list_del_entry_valid+0x42/0x80
[ 5694.961820] CPU: 33 PID: 418824 Comm: fuse_counters.s Kdump: loaded Tainted: G S 5.19.0-0_fbk3_rc3_hoangnhatpzsdynshrv41_10870_g85a9558a25de #1
[ 5694.990194] Hardware name: Wiwynn Twin Lakes MP/Twin Lakes Passive MP, BIOS YMM16 05/24/2021
[ 5695.007072] RIP: 0010:__list_del_entry_valid+0x42/0x80
[ 5695.017351] Code: 08 48 83 c2 22 48 39 d0 74 24 48 8b 10 48 39 f2 75 2c 48 8b 51 08 b0 01 48 39 f2 75 34 c3 48 c7 c7 55 d7 78 82 e8 4e 45 3b 00 <0f> 0b eb 31 48 c7 c7 27 a8 70 82 e8 3e 45 3b 00 0f 0b eb 21 48 c7
[ 5695.054919] RSP: 0018:ffffc90027aef4f0 EFLAGS: 00010246
[ 5695.065366] RAX: 41fe484987275300 RBX: ffff888008988180 RCX: 0000000000000000
[ 5695.079636] RDX: ffff88886006c280 RSI: ffff888860060480 RDI: ffff888860060480
[ 5695.093904] RBP: 0000000000000002 R08: 0000000000000000 R09: ffffc90027aef370
[ 5695.108175] R10: 0000000000000000 R11: ffffffff82fdf1c0 R12: 0000000010000002
[ 5695.122447] R13: ffff888014b6a448 R14: ffff888014b6a420 R15: 00000000138dc240
[ 5695.136717] FS: 00007f23a7d3f740(0000) GS:ffff888860040000(0000) knlGS:0000000000000000
[ 5695.152899] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5695.164388] CR2: 0000560ceaab6ac0 CR3: 000000001c06c001 CR4: 00000000007706e0
[ 5695.178659] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 5695.192927] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 5695.207197] PKRU: 55555554
[ 5695.212602] Call Trace:
[ 5695.217486] <TASK>
[ 5695.221674] zs_map_object+0x91/0x270
[ 5695.229000] zswap_frontswap_store+0x33d/0x870
[ 5695.237885] ? do_raw_spin_lock+0x5d/0xa0
[ 5695.245899] __frontswap_store+0x51/0xb0
[ 5695.253742] swap_writepage+0x3c/0x60
[ 5695.261063] shrink_page_list+0x738/0x1230
[ 5695.269255] shrink_lruvec+0x5ec/0xcd0
[ 5695.276749] ? shrink_slab+0x187/0x5f0
[ 5695.284240] ? mem_cgroup_iter+0x6e/0x120
[ 5695.292255] shrink_node+0x293/0x7b0
[ 5695.299402] do_try_to_free_pages+0xea/0x550
[ 5695.307940] try_to_free_pages+0x19a/0x490
[ 5695.316126] __folio_alloc+0x19ff/0x3e40
[ 5695.323971] ? __filemap_get_folio+0x8a/0x4e0
[ 5695.332681] ? walk_component+0x2a8/0xb50
[ 5695.340697] ? generic_permission+0xda/0x2a0
[ 5695.349231] ? __filemap_get_folio+0x8a/0x4e0
[ 5695.357940] ? walk_component+0x2a8/0xb50
[ 5695.365955] vma_alloc_folio+0x10e/0x570
[ 5695.373796] ? walk_component+0x52/0xb50
[ 5695.381634] wp_page_copy+0x38c/0xc10
[ 5695.388953] ? filename_lookup+0x378/0xbc0
[ 5695.397140] handle_mm_fault+0x87f/0x1800
[ 5695.405157] do_user_addr_fault+0x1bd/0x570
[ 5695.413520] exc_page_fault+0x5d/0x110
[ 5695.421017] asm_exc_page_fault+0x22/0x30
After some investigation, I have found the following issue: unlike other
zswap backends, zsmalloc performs the LRU list update at the object
mapping time, rather than when the slot for the object is allocated.
This deviation was discussed and agreed upon during the review process
of the zsmalloc writeback patch series:
https://lore.kernel.org/lkml/Y3flcAXNxxrvy3ZH@cmpxchg.org/
Unfortunately, this introduces a subtle bug that occurs when there is a
concurrent store and reclaim, which interleave as follows:
zswap_frontswap_store() shrink_worker()
zs_malloc() zs_zpool_shrink()
spin_lock(&pool->lock) zs_reclaim_page()
zspage = find_get_zspage()
spin_unlock(&pool->lock)
spin_lock(&pool->lock)
zspage = list_first_entry(&pool->lru)
---truncated--- |
