Overview
- Description
- 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.
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- NVD status
- Analyzed
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 7.8
- Impact score
- 5.9
- Exploitability score
- 1.8
- Vector string
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Severity
- HIGH
Weaknesses
- nvd@nist.gov
- CWE-416
Social media
- Hype score
- Not currently trending
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D4F8C11A-E708-4EBE-97BC-D7F6041074D6",
"versionEndExcluding": "4.19.320",
"versionStartIncluding": "3.4"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A8961D98-9ACF-4188-BA88-44038B14BC28",
"versionEndExcluding": "5.4.282",
"versionStartIncluding": "4.20"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5CCEDF13-293D-4E64-B501-4409D0365AFE",
"versionEndExcluding": "5.10.224",
"versionStartIncluding": "5.5"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B4E2B568-3171-41DE-B519-F2B1A3600D94",
"versionEndExcluding": "5.15.165",
"versionStartIncluding": "5.11"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "20DB9042-F89E-4024-B005-ACBBA99CA659",
"versionEndExcluding": "6.1.104",
"versionStartIncluding": "5.16"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6ED8FBDF-48EE-4FEB-8B1A-CFF4FBCB27BF",
"versionEndExcluding": "6.6.45",
"versionStartIncluding": "6.2"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1F9FECDC-6CB8-41E5-B32A-E46776100D9C",
"versionEndExcluding": "6.10.4",
"versionStartIncluding": "6.7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8B3CE743-2126-47A3-8B7C-822B502CF119"
}
],
"operator": "OR"
}
]
}
]