CVE-2026-43011

net/x25: Fix potential double free of skb

State
Published
Severity
9.8 Critical
Published
May 1, 2026
Updated
Oct 19, 2026
Reserved
May 1, 2026

Read the record on cve.org

Description

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

net/x25: Fix potential double free of skb

When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain:

x25_queue_rx_frame returns 1 | v x25_state3_machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25_process_rx_frame returns queued=0 | v x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb) again

This would free the same skb twice. Looking at x25_backlog_rcv:

net/x25/x25_in.c:x25_backlog_rcv() { ... queued = x25_process_rx_frame(sk, skb); ... if (!queued) kfree_skb(skb); }

Scores

CVSSScoreVectorSource
3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

Affected Products

ProductVersions
LinuxLinux
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 5d0aa038a90b30c9bedde0c41c1fdcd98ecb16e9Affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 3f5e3005984645bf5bd129c6b13149879580b1fbAffected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f782dd382203b2a8c4552a628431b7de65a19a7bAffected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 143d4fa68ae9efb83b0c55b12cc7f0d03732a2b1Affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 524371398d8463ea7e101fce2cbf3915645d1730Affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before fa1dbc93530b34fab0da9862426fe9c918c74dc0Affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before c87dd137c0dad07cc55f98181ff380b0c23d2878Affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before d10a26aa4d072320530e6968ef945c8c575edf61Affected
LinuxLinux
  • 2.6.12Affected
  • before 2.6.12Not affected
  • 5.10.253 through 5.10.*Not affected
  • 5.15.203 through 5.15.*Not affected
  • 6.1.168 through 6.1.*Not affected
  • 6.6.134 through 6.6.*Not affected
  • 6.12.81 through 6.12.*Not affected
  • 6.18.22 through 6.18.*Not affected
  • 6.19.12 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

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