Description
In the Linux kernel, the following vulnerability has been resolved:
net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot
On the SMC-D client, slot 0 of ini->ism_dev[]/ini->ism_chid[] is reserved for an SMC-Dv1 device. smc_find_ism_v2_device_clnt() populates V2 entries starting at index 1, so when no V1 device is selected slot 0 is left in its kzalloc()'ed state with ism_dev[0] == NULL and ism_chid[0] == 0.
smc_v2_determine_accepted_chid() then matches the peer's CHID against the array starting from index 0 using the CHID alone. A malicious peer replying to a SMC-Dv2-only proposal with d1.chid == 0 matches the empty slot, ini->ism_selected becomes 0, and the subsequent ism_dev[0]->lgr_lock dereference in smc_conn_create() faults at offsetof(struct smcd_dev, lgr_lock) == 0x68:
BUG: KASAN: null-ptr-deref in _raw_spin_lock_bh+0x79/0xe0 Write of size 4 at addr 0000000000000068 by task exploit/144 Call Trace: _raw_spin_lock_bh smc_conn_create (net/smc/smc_core.c:1997) __smc_connect (net/smc/af_smc.c:1447) smc_connect (net/smc/af_smc.c:1720) __sys_connect __x64_sys_connect do_syscall_64
Require ism_dev[i] to be non-NULL before accepting a CHID match.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < 903f7688ffeb9b323d70652c01f554bd4ba2a3d6; >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0; >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < 6927cacf2b10d4fa80c1a2d407512ef9397c59c6; >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0; >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < 53eb7bd09aace72fa17510d80e0caf5ca058c231; >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < afa9036b8c9963947b487c36e332df6a42c96fcb; >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < 65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e; >= a7c9c5f4af7f6098da68705fc5d86565d0728ef7, < 277740023def559a4a2ddc3e8e784ee37a0f16a9 |
| Linux | Linux | 5.10 |
References
- https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9Patch
- https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231Patch
- https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4ePatch
- https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6Patch
- https://git.kernel.org/stable/c/903f7688ffeb9b323d70652c01f554bd4ba2a3d6Patch
- https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcbPatch
- https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0Patch
- https://git.kernel.org/stable/c/dd2f9dd83c68abd7ba7ded7075290b016cb7ecd0Patch
Timeline
- Published
- Jul 19, 2026
- Last modified
- Oct 19, 2026
- NVD status
- Modified