CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
Low
EPSS
Percentile
5.1%
In the Linux kernel, the following vulnerability has been resolved:
erofs: fix pcluster use-after-free on UP platforms
During stress testing with CONFIG_SMP disabled, KASAN reports as below:
==================================================================
BUG: KASAN: use-after-free in __mutex_lock+0xe5/0xc30
Read of size 8 at addr ffff8881094223f8 by task stress/7789
CPU: 0 PID: 7789 Comm: stress Not tainted 6.0.0-rc1-00002-g0d53d2e882f9 #3
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
<TASK>
…
__mutex_lock+0xe5/0xc30
…
z_erofs_do_read_page+0x8ce/0x1560
…
z_erofs_readahead+0x31c/0x580
…
Freed by task 7787
kasan_save_stack+0x1e/0x40
kasan_set_track+0x20/0x30
kasan_set_free_info+0x20/0x40
__kasan_slab_free+0x10c/0x190
kmem_cache_free+0xed/0x380
rcu_core+0x3d5/0xc90
__do_softirq+0x12d/0x389
Last potentially related work creation:
kasan_save_stack+0x1e/0x40
__kasan_record_aux_stack+0x97/0xb0
call_rcu+0x3d/0x3f0
erofs_shrink_workstation+0x11f/0x210
erofs_shrink_scan+0xdc/0x170
shrink_slab.constprop.0+0x296/0x530
drop_slab+0x1c/0x70
drop_caches_sysctl_handler+0x70/0x80
proc_sys_call_handler+0x20a/0x2f0
vfs_write+0x555/0x6c0
ksys_write+0xbe/0x160
do_syscall_64+0x3b/0x90
The root cause is that erofs_workgroup_unfreeze() doesn’t reset to
orig_val thus it causes a race that the pcluster reuses unexpectedly
before freeing.
Since UP platforms are quite rare now, such path becomes unnecessary.
Let’s drop such specific-designed path directly instead.
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/erofs/internal.h"
],
"versions": [
{
"version": "73f5c66df3e2",
"lessThan": "8ddd001cef5e",
"status": "affected",
"versionType": "git"
},
{
"version": "73f5c66df3e2",
"lessThan": "94c34faaafe7",
"status": "affected",
"versionType": "git"
},
{
"version": "73f5c66df3e2",
"lessThan": "2f44013e3998",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/erofs/internal.h"
],
"versions": [
{
"version": "5.0",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.0",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.68",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.19.9",
"lessThanOrEqual": "5.19.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.0",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]