CVE-2026-52993

tipc: fix double-free in tipc_buf_append()

State: Published
Severity: 9.8 Critical
Published: Jun 24, 2026
Updated: Oct 19, 2026
Reserved: Jun 9, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

tipc: fix double-free in tipc_buf_append()

tipc_msg_validate() can potentially reallocate the skb it is validating, freeing the old one. In tipc_buf_append(), it was being called with a pointer to a local variable which was a copy of the caller's skb pointer.

If the skb was reallocated and validation subsequently failed, the error handling path would free the original skb pointer, which had already been freed, leading to double-free.

Fix this by checking if head now points to a newly allocated reassembled skb. If it does, reassign *headbuf for later freeing operations.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux
3.1	7.0 High	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H	redhat-SADP

Weaknesses

CWE-763 Release of Invalid Pointer or Reference

Affected Products

Product	Versions
LinuxLinux	d618d09a68e4eed7a435beb2e355250f6f40664a to before a438975a6dcdbd70865978c021650d1485586f0bAffected d618d09a68e4eed7a435beb2e355250f6f40664a to before 4ee4deadaae7cb2e3d53af0fc889cf92a73413c0Affected d618d09a68e4eed7a435beb2e355250f6f40664a to before d3556656c6daebf8def751c7e71d11dd0a180d24Affected d618d09a68e4eed7a435beb2e355250f6f40664a to before 0274f24485fc38032d4093e463dc3ff5c7a667c9Affected d618d09a68e4eed7a435beb2e355250f6f40664a to before 4d104882bc815d4ec666ace9155f5f52715879a6Affected d618d09a68e4eed7a435beb2e355250f6f40664a to before 1d5e589055880fae229e229e1929e087dbe08cf3Affected d618d09a68e4eed7a435beb2e355250f6f40664a to before 29940fff14110ca48c5ccc168d121665b51bb778Affected d618d09a68e4eed7a435beb2e355250f6f40664a to before d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3aAffected
LinuxLinux	4.15Affected before 4.15Not affected 5.10.258 through 5.10.Not affected 5.15.209 through 5.15.Not affected 6.1.175 through 6.1.Not affected 6.6.141 through 6.6.Not affected 6.12.91 through 6.12.Not affected 6.18.33 through 6.18.Not affected 7.0.10 through 7.0.*Not affected 7.1 and laterNot affected

Product

Versions

LinuxLinux

d618d09a68e4eed7a435beb2e355250f6f40664a to before a438975a6dcdbd70865978c021650d1485586f0bAffected
d618d09a68e4eed7a435beb2e355250f6f40664a to before 4ee4deadaae7cb2e3d53af0fc889cf92a73413c0Affected
d618d09a68e4eed7a435beb2e355250f6f40664a to before d3556656c6daebf8def751c7e71d11dd0a180d24Affected
d618d09a68e4eed7a435beb2e355250f6f40664a to before 0274f24485fc38032d4093e463dc3ff5c7a667c9Affected
d618d09a68e4eed7a435beb2e355250f6f40664a to before 4d104882bc815d4ec666ace9155f5f52715879a6Affected
d618d09a68e4eed7a435beb2e355250f6f40664a to before 1d5e589055880fae229e229e1929e087dbe08cf3Affected
d618d09a68e4eed7a435beb2e355250f6f40664a to before 29940fff14110ca48c5ccc168d121665b51bb778Affected
d618d09a68e4eed7a435beb2e355250f6f40664a to before d293ca716e7d5dffdaecaf6b9b2f857a33dc3d3aAffected

LinuxLinux

4.15Affected
before 4.15Not affected
5.10.258 through 5.10.*Not affected
5.15.209 through 5.15.*Not affected
6.1.175 through 6.1.*Not affected
6.6.141 through 6.6.*Not affected
6.12.91 through 6.12.*Not affected
6.18.33 through 6.18.*Not affected
7.0.10 through 7.0.*Not affected
7.1 and laterNot affected

References

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