AI Score
Confidence
Low
EPSS
Percentile
15.5%
SSVC
Exploitation
none
Automatable
no
Technical Impact
partial
In the Linux kernel, the following vulnerability has been resolved:
blk-iocost: do not WARN if iocg was already offlined
In iocg_pay_debt(), warn is triggered if ‘active_list’ is empty, which
is intended to confirm iocg is active when it has debt. However, warn
can be triggered during a blkcg or disk removal, if iocg_waitq_timer_fn()
is run at that time:
WARNING: CPU: 0 PID: 2344971 at block/blk-iocost.c:1402 iocg_pay_debt+0x14c/0x190
Call trace:
iocg_pay_debt+0x14c/0x190
iocg_kick_waitq+0x438/0x4c0
iocg_waitq_timer_fn+0xd8/0x130
__run_hrtimer+0x144/0x45c
__hrtimer_run_queues+0x16c/0x244
hrtimer_interrupt+0x2cc/0x7b0
The warn in this situation is meaningless. Since this iocg is being
removed, the state of the ‘active_list’ is irrelevant, and ‘waitq_timer’
is canceled after removing ‘active_list’ in ioc_pd_free(), which ensures
iocg is freed after iocg_waitq_timer_fn() returns.
Therefore, add the check if iocg was already offlined to avoid warn
when removing a blkcg or disk.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "1da177e4c3f4",
"lessThan": "1c172ac7afe4",
"versionType": "git"
},
{
"status": "affected",
"version": "1da177e4c3f4",
"lessThan": "14b3275f93d4",
"versionType": "git"
},
{
"status": "affected",
"version": "1da177e4c3f4",
"lessThan": "01bc4fda9ea0",
"versionType": "git"
}
],
"programFiles": [
"block/blk-iocost.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "unaffected",
"version": "6.6.31",
"versionType": "custom",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.8.10",
"versionType": "custom",
"lessThanOrEqual": "6.8.*"
},
{
"status": "unaffected",
"version": "6.9",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"block/blk-iocost.c"
],
"defaultStatus": "affected"
}
]