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
High
EPSS
Percentile
5.0%
In the Linux kernel, the following vulnerability has been resolved:
net/iucv: fix use after free in iucv_sock_close()
iucv_sever_path() is called from process context and from bh context.
iucv->path is used as indicator whether somebody else is taking care of
severing the path (or it is already removed / never existed).
This needs to be done with atomic compare and swap, otherwise there is a
small window where iucv_sock_close() will try to work with a path that has
already been severed and freed by iucv_callback_connrej() called by
iucv_tasklet_fn().
Example:
[452744.123844] Call Trace:
[452744.123845] ([<0000001e87f03880>] 0x1e87f03880)
[452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138
[452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv]
[452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv]
[452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv]
[452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8
[452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48
[452744.124820] [<00000000d5421642>] __fput+0xba/0x268
[452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0
[452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90
[452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8
[452744.125319] Last Breaking-Event-Address:
[452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138
[452744.125324]
[452744.125325] Kernel panic - not syncing: Fatal exception in interrupt
Note that bh_lock_sock() is not serializing the tasklet context against
process context, because the check for sock_owned_by_user() and
corresponding handling is missing.
Ideas for a future clean-up patch:
A) Correct usage of bh_lock_sock() in tasklet context, as described in
Re-enqueue, if needed. This may require adding return values to the
tasklet functions and thus changes to all users of iucv.
B) Change iucv tasklet into worker and use only lock_sock() in af_iucv.
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | 6.11 | cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"net/iucv/af_iucv.c"
],
"versions": [
{
"version": "7d316b945352",
"lessThan": "84f40b46787e",
"status": "affected",
"versionType": "git"
},
{
"version": "7d316b945352",
"lessThan": "37652fbef980",
"status": "affected",
"versionType": "git"
},
{
"version": "7d316b945352",
"lessThan": "c65f72eec60a",
"status": "affected",
"versionType": "git"
},
{
"version": "7d316b945352",
"lessThan": "ac758e1f663f",
"status": "affected",
"versionType": "git"
},
{
"version": "7d316b945352",
"lessThan": "8b424c9e4411",
"status": "affected",
"versionType": "git"
},
{
"version": "7d316b945352",
"lessThan": "01437282fd39",
"status": "affected",
"versionType": "git"
},
{
"version": "7d316b945352",
"lessThan": "69620522c48c",
"status": "affected",
"versionType": "git"
},
{
"version": "7d316b945352",
"lessThan": "f558120cd709",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"net/iucv/af_iucv.c"
],
"versions": [
{
"version": "3.4",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.4",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.19.320",
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.4.282",
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.224",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.165",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.1.104",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.45",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.10.4",
"lessThanOrEqual": "6.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.11",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/01437282fd3904810603f3dc98d2cac6b8b6fc84
git.kernel.org/stable/c/37652fbef9809411cea55ea5fa1a170e299efcd0
git.kernel.org/stable/c/69620522c48ce8215e5eb55ffbab8cafee8f407d
git.kernel.org/stable/c/84f40b46787ecb67c7ad08a5bb1376141fa10c01
git.kernel.org/stable/c/8b424c9e44111c5a76f41c6b741f8d4c4179d876
git.kernel.org/stable/c/ac758e1f663fe9bc64f6b47212a2aa18697524f5
git.kernel.org/stable/c/c65f72eec60a34ace031426e04e9aff8e5f04895
git.kernel.org/stable/c/f558120cd709682b739207b48cf7479fd9568431