CVE-2022-50335
published 2025-09-15CVE-2022-50335: In the Linux kernel, the following vulnerability has been resolved: 9p: set req refcount to zero to avoid uninitialized usage When a new request is allocated…
PriorityP422medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.35%
27.6th percentile
In the Linux kernel, the following vulnerability has been resolved:
9p: set req refcount to zero to avoid uninitialized usage
When a new request is allocated, the refcount will be zero if it is
reused, but if the request is newly allocated from slab, it is not fully
initialized before being added to idr.
If the p9_read_work got a response before the refcount initiated. It will
use a uninitialized req, which will result in a bad request data struct.
Here is the logs from syzbot.
Corrupted memory at 0xffff88807eade00b [ 0xff 0x07 0x00 0x00 0x00 0x00
0x00 0x00 . . . . . . . . ] (in kfence-#110):
p9_fcall_fini net/9p/client.c:248 [inline]
p9_req_put net/9p/client.c:396 [inline]
p9_req_put+0x208/0x250 net/9p/client.c:390
p9_client_walk+0x247/0x540 net/9p/client.c:1165
clone_fid fs/9p/fid.h:21 [inline]
v9fs_fid_xattr_set+0xe4/0x2b0 fs/9p/xattr.c:118
v9fs_xattr_set fs/9p/xattr.c:100 [inline]
v9fs_xattr_handler_set+0x6f/0x120 fs/9p/xattr.c:159
__vfs_setxattr+0x119/0x180 fs/xattr.c:182
__vfs_setxattr_noperm+0x129/0x5f0 fs/xattr.c:216
__vfs_setxattr_locked+0x1d3/0x260 fs/xattr.c:277
vfs_setxattr+0x143/0x340 fs/xattr.c:309
setxattr+0x146/0x160 fs/xattr.c:617
path_setxattr+0x197/0x1c0 fs/xattr.c:636
__do_sys_setxattr fs/xattr.c:652 [inline]
__se_sys_setxattr fs/xattr.c:648 [inline]
__ia32_sys_setxattr+0xc0/0x160 fs/xattr.c:648
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x70/0x82
Below is a similar scenario, the scenario in the syzbot log looks more
complicated than this one, but this patch can fix it.
T21124 p9_read_work
======================== second trans =================================
p9_client_walk
p9_client_rpc
p9_client_prepare_req
p9_tag_alloc
req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
tag = idr_alloc
>
req->tc.tag = tag;
/* req->[refcount/tag] == uninitialized */
m->rreq = p9_tag_lookup(m-
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.1.4-1 (bookworm) | linux 6.1.4-1 (bookworm) |
| linux | linux | — | — |
| linux | linux | — | — |
| linux | linux | >= 4.19.57 < 4.20 | 4.20 |
| linux | linux | >= 728356dedeff8ef999cb436c71333ef4ac51a81c < 1cabce56626a61f4f02452cba61ad4332a4b73f8 | 1cabce56626a61f4f02452cba61ad4332a4b73f8 |
| linux | linux | >= 728356dedeff8ef999cb436c71333ef4ac51a81c < 73c47b3123b351de2d3714a72a336c0f72f203af | 73c47b3123b351de2d3714a72a336c0f72f203af |
| linux | linux | >= 728356dedeff8ef999cb436c71333ef4ac51a81c < 967fc34f297e40fd2e068cf6b0c3eb4916228539 | 967fc34f297e40fd2e068cf6b0c3eb4916228539 |
| linux | linux | >= 728356dedeff8ef999cb436c71333ef4ac51a81c < 26273ade77f54716e30dfd40ac6e85ceb54ac0f9 | 26273ade77f54716e30dfd40ac6e85ceb54ac0f9 |
| linux | linux_kernel | >= 0 < 6.1.4-1 | 6.1.4-1 |
| linux | linux_kernel | >= 0 < 6.1.4-1 | 6.1.4-1 |
| linux | linux_kernel | >= 0 < 6.1.4-1 | 6.1.4-1 |
| linux | linux_kernel | >= 4.19.57 < 5.15.86 | 5.15.86 |
| linux | linux_kernel | >= 5.16 < 6.0.16 | 6.0.16 |
| linux | linux_kernel | >= 6.1 < 6.1.2 | 6.1.2 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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Red Hat
kernel: 9p: set req refcount to zero to avoid uninitialized usage
vendor_redhat·2025-09-15·CVSS 5.5
CVE-2022-50335 [MEDIUM] kernel: 9p: set req refcount to zero to avoid uninitialized usage
kernel: 9p: set req refcount to zero to avoid uninitialized usage
In the Linux kernel, the following vulnerability has been resolved:
9p: set req refcount to zero to avoid uninitialized usage
When a new request is allocated, the refcount will be zero if it is
reused, but if the request is newly allocated from slab, it is not fully
initialized before being added to idr.
If the p9_read_work got a response before the refcount initiated. It will
use a uninitialized req, which will result in a bad request data struct.
Here is the logs from syzbot.
Corrupted memory at 0xffff88807eade00b [ 0xff 0x07 0x00 0x00 0x00 0x00
0x00 0x00 . . . . . . . . ] (in kfence-#110):
p9_fcall_fini net/9p/client.c:248 [inline]
p9_req_put net/9p/client.c:396 [inline]
p9_req_put+0x208/0x250 net/9p/client.c:390
p9_clie
Debian
CVE-2022-50335: linux - In the Linux kernel, the following vulnerability has been resolved: 9p: set req...
vendor_debian·2022·CVSS 5.5
CVE-2022-50335 [MEDIUM] CVE-2022-50335: linux - In the Linux kernel, the following vulnerability has been resolved: 9p: set req...
In the Linux kernel, the following vulnerability has been resolved: 9p: set req refcount to zero to avoid uninitialized usage When a new request is allocated, the refcount will be zero if it is reused, but if the request is newly allocated from slab, it is not fully initialized before being added to idr. If the p9_read_work got a response before the refcount initiated. It will use a uninitialized req, which will result in a bad request data struct. Here is the logs from syzbot. Corrupted memory at 0xffff88807eade00b [ 0xff 0x07 0x00 0x00 0x00 0x00 0x00 0x00 . . . . . . . . ] (in kfence-#110): p9_fcall_fini net/9p/client.c:248 [inline] p9_req_put net/9p/client.c:396 [inline] p9_req_put+0x208/0x250 net/9p/client.c:390 p9_client_walk+0x247/0x540 net/9p/client.c:1165 clone_fid fs/9p/fid.h:21 [
GHSA
GHSA-pq2h-q77j-f595: In the Linux kernel, the following vulnerability has been resolved:
9p: set req refcount to zero to avoid uninitialized usage
When a new request is
ghsa_unreviewed·2025-09-15
CVE-2022-50335 [MEDIUM] CWE-908 GHSA-pq2h-q77j-f595: In the Linux kernel, the following vulnerability has been resolved:
9p: set req refcount to zero to avoid uninitialized usage
When a new request is
In the Linux kernel, the following vulnerability has been resolved:
9p: set req refcount to zero to avoid uninitialized usage
When a new request is allocated, the refcount will be zero if it is
reused, but if the request is newly allocated from slab, it is not fully
initialized before being added to idr.
If the p9_read_work got a response before the refcount initiated. It will
use a uninitialized req, which will result in a bad request data struct.
Here is the logs from syzbot.
Corrupted memory at 0xffff88807eade00b [ 0xff 0x07 0x00 0x00 0x00 0x00
0x00 0x00 . . . . . . . . ] (in kfence-#110):
p9_fcall_fini net/9p/client.c:248 [inline]
p9_req_put net/9p/client.c:396 [inline]
p9_req_put+0x208/0x250 net/9p/client.c:390
p9_client_walk+0x247/0x540 net/9p/client.c:1165
clone_fid fs/9p/fid.h
OSV
CVE-2022-50335: In the Linux kernel, the following vulnerability has been resolved: 9p: set req refcount to zero to avoid uninitialized usage When a new request is al
osv·2025-09-15·CVSS 5.5
CVE-2022-50335 [MEDIUM] CVE-2022-50335: In the Linux kernel, the following vulnerability has been resolved: 9p: set req refcount to zero to avoid uninitialized usage When a new request is al
In the Linux kernel, the following vulnerability has been resolved: 9p: set req refcount to zero to avoid uninitialized usage When a new request is allocated, the refcount will be zero if it is reused, but if the request is newly allocated from slab, it is not fully initialized before being added to idr. If the p9_read_work got a response before the refcount initiated. It will use a uninitialized req, which will result in a bad request data struct. Here is the logs from syzbot. Corrupted memory at 0xffff88807eade00b [ 0xff 0x07 0x00 0x00 0x00 0x00 0x00 0x00 . . . . . . . . ] (in kfence-#110): p9_fcall_fini net/9p/client.c:248 [inline] p9_req_put net/9p/client.c:396 [inline] p9_req_put+0x208/0x250 net/9p/client.c:390 p9_client_walk+0x247/0x540 net/9p/client.c:1165 clone_fid fs/9p/fid.h:21 [
No detection rules found.
No public exploits indexed.
2025-09-15
Published