net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put

Summary

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: E-Switch: fix use-after-free in mlx5_eswitch_termtbl_put In mlx5_eswitch_termtbl_put(), the zero-ref cleanup check reads tt->ref_count after termtbl_mutex has been released. Two concurrent callers on the same mlx5_termtbl_handle race: one decrements ref_count to zero, removes the hash entry, and calls kfree(tt) while the other has already dropped the mutex and is about to evaluate if (!tt->ref_count), producing a use-after-free. Fix this by capturing the result of the decrement into a stack-local last variable before dropping the mutex. The cleanup decision is now made entirely under termtbl_mutex, and tt is not touched after kfree.

Timeline

1. Sep 25, 2026, 10:23 AM UTCCVE published
2. Oct 19, 2026, 9:12 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in e3ee194a790896fa92fea20b5385a354be2f2c12; From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in b1398c9dfb5d3d4faaf6905ff7d98110a5d2c797; From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in 92f581cac93a71723456ac79ef54d9f60a251b42; From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in a5833fdf53350b8b95a558fcf0056ddb1c0fe154; From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in 304ea40ef4561671503c36e47da44a0a31b71e36; From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in e393789e92310d7c66f57c876101779c90816a12; From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in 18b2969073879b9cce24e1a78b118bdad54518d1; From 10caabdaad5ace85577a453da97d1f8d3b944427 · fixed in 7ee07f601f8f507c9faf25c68a49396ab8950596

• Linux Linux

  5.3

• KernelLinux

  From 5.3.0 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53; From 6.19.0 · fixed in 7.2.7

References 8