CVE-2026-45891net: hns3: fix double free issue for tx spare buffer

Official description

In the Linux kernel, the following vulnerability has been resolved: net: hns3: fix double free issue for tx spare buffer In hns3_set_ringparam(), a temporary copy (tmp_rings) of the ring structure is created for rollback. However, the tx_spare pointer in the original ring handle is incorrectly left pointing to the old backup memory. Later, if memory allocation fails in hns3_init_all_ring() during the setup, the error path attempts to free all newly allocated rings. Since tx_spare contains a stale (non-NULL) pointer from the backup, it is mistaken for a newly allocated buffer and is erroneously freed, leading to a double-free of the backup memory. The root cause is that the tx_spare field was not cleared after its value was saved in tmp_rings, leaving a dangling pointer. Fix this by setting tx_spare to NULL in the original ring structure when the creation of the new `tx_spare` fails. This ensures the error cleanup path only frees genuinely newly allocated buffers.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/fb6a4c376d454b425555b1b0bda36e99f56ec307
• https://git.kernel.org/stable/c/43015461662d41dcfb3bb95fadd8a2a42ad8eacf
• https://git.kernel.org/stable/c/6dc10494cfe27b6f1e9adb7e293293ae39c50b7c
• https://git.kernel.org/stable/c/d2c785733dfb853ea0b53984c75662a1af230a94
• https://git.kernel.org/stable/c/fdbccddb7e7822016601829f95de4008e193f7bc
• https://git.kernel.org/stable/c/c3659273860bed0c8e573b865e3769abc51225a8
• https://git.kernel.org/stable/c/6d2f142b1e4b203387a92519d9d2e34752a79dbb