CVE-2026-74426afs: fix NULL pointer dereference in afs_get_tree()

Official description

In the Linux kernel, the following vulnerability has been resolved: afs: fix NULL pointer dereference in afs_get_tree() afs_alloc_sbi() uses kzalloc for memory allocation. And, if ctx->dyn_root is not null, as->cell and as->volume are null. In trace_afs_get_tree() they are dereferenced. KASAN error message: KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 2 PID: 18478 Comm: syz-executor.7 Not tainted 5.10.246-syzkaller #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:perf_trace_afs_get_tree+0x1d9/0x550 include/trace/events/afs.h:1365 Call Trace: trace_afs_get_tree include/trace/events/afs.h:1365 [inline] afs_get_tree+0x922/0x1350 fs/afs/super.c:599 vfs_get_tree+0x8e/0x300 fs/super.c:1572 do_new_mount fs/namespace.c:3011 [inline] path_mount+0x14a5/0x2220 fs/namespace.c:3341 do_mount fs/namespace.c:3354 [inline] __do_sys_mount fs/namespace.c:3562 [inline] __se_sys_mount fs/namespace.c:3539 [inline] __x64_sys_mount+0x283/0x300 fs/namespace.c:3539 do_syscall_64+0x33/0x50 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/67fb48c4a0874953212321cd5d57fdb4900dbc31
• https://git.kernel.org/stable/c/d648cc2069eb081707c061849046d909f57c78b1
• https://git.kernel.org/stable/c/d5b17474feed3c30991f07affa2473adbad95055
• https://git.kernel.org/stable/c/867b3ea146a041023bfcd258e6db516b1bb28f19
• https://git.kernel.org/stable/c/ea19edf71721cd42f923e3c70f4ff995b422fe3b
• https://git.kernel.org/stable/c/23b3d457d8387bcb2a61063a9e520063ada9335f
• https://git.kernel.org/stable/c/70b2842734d831c908474779bb8a76daf55f782c
• https://git.kernel.org/stable/c/0b70716081c6462be9b2928ad736d0d527b09678