PT-2026-61365 · Linux · Linux

CVE-2026-64048 · Published 2026-07-19 · Updated 2026-07-19

Mitre

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Fix

Related Identifiers

CVE-2026-64048

Affected Products

Linux

References · 7

• https://nvd.nist.gov/vuln/detail/CVE-2026-64048 · Security Note
• https://git.kernel.org/stable/c/65edb3b0822cfe5041be8fbabebd57e2e5ad9f4e · Note
• https://git.kernel.org/stable/c/afa9036b8c9963947b487c36e332df6a42c96fcb · Note
• https://git.kernel.org/stable/c/6927cacf2b10d4fa80c1a2d407512ef9397c59c6 · Note
• https://git.kernel.org/stable/c/53eb7bd09aace72fa17510d80e0caf5ca058c231 · Note
• https://git.kernel.org/stable/c/d38ba387244e5c5f7db3e11ea98bc2c7beccb0c0 · Note
• https://git.kernel.org/stable/c/277740023def559a4a2ddc3e8e784ee37a0f16a9 · Note