CVE-2026-93809 drm/amdgpu: flush pending RCU callbacks on module unload
A use-after-free vulnerability in the amdgpu driver allows local attackers to cause a system crash or potentially execute code by triggering RCU callbacks after module unload.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93809?
CVE-2026-93809 is an use after free vulnerability in Linux, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: flush pending RCU callbacks on module unload
Call rcu_barrier() in module exit to wait for outstanding call_rcu() callbacks before freeing module text, preventing late callback execution in freed memory.
BUG: unable to handle page fault for address: ffffffffc1d59c40 PGD 6a12067 P4D 6a12067 PUD 6a14067 PMD 13698b067 PTE 0 Oops: 0010 [#1] SMP NOPTI RIP: 0010:0xffffffffc1d59c40 Code: Unable to access opcode bytes at RIP 0xffffffffc1d59c16. RSP: 0018:ffffc900198c0f28 EFLAGS: 00010286 RAX: ffffffffc1d59c40 RBX: ffff897c7d6b61c0 RCX: ffff88826aff4590 RDX: ffff8884d8b35490 RSI: ffffc900198c0f30 RDI: ffff88812af67290 RBP: 000000000000000a (DONE segment entries) R08: 0000000000000000 R09: 0000000000000100 R10: 0000000000000000 R11: ffffffff82a06100 R12: ffff88811a4e3700 R13: 0000000000000000 R14: ffff897c7d6b6270 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff897c7d680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffc1d59c16 CR3: 00000104a980a001 CR4: 0000000002770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> ? rcu_do_batch+0x163/0x450 ? rcu_core+0x177/0x1c0 ? __do_softirq+0xc1/0x280 ? asm_call_irq_on_stack+0xf/0x20 </IRQ> ? do_softirq_own_stack+0x37/0x50 ? irq_exit_rcu+0xc4/0x100 ? sysvec_apic_timer_interrupt+0x36/0x80 ? asm_sysvec_apic_timer_interrupt+0x12/0x20 ? cpuidle_enter_state+0xd4/0x360 ? cpuidle_enter+0x29/0x40 ? cpuidle_idle_call+0x108/0x1a0 ? do_idle+0x77/0xf0 ? cpu_startup_entry+0x19/0x20 ? secondary_startup_64_no_verify+0xbf/0xcb
(cherry picked from commit feaa5039f6c12acc9aa934c2d45dcd251a12c69f)
Which versions are affected by CVE-2026-93809?
How do I fix CVE-2026-93809?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-93809 being exploited?
There is no known exploitation of CVE-2026-93809 in the wild and no public exploit code.
Sources
Also known as AZL-103901, DEBIAN-CVE-2026-93809, GHSA-h4gf-5w5m-m3j2, UBUNTU-CVE-2026-93809.