Levi Zim <rsworktech@xxxxxxxxxxx> writes:
> On 2024-12-04 09:01, Cong Wang wrote:
>> On Sun, Dec 01, 2024 at 09:42:08AM +0800, Levi Zim wrote:
>>> On 2024-11-30 21:38, Levi Zim via B4 Relay wrote:
>>>> I found that bpf kselftest sockhash::test_txmsg_cork_hangs in
>>>> test_sockmap.c triggers a kernel NULL pointer dereference:
>> Interesting, I also ran this test recently and I didn't see such a
>> crash.
>
> I am also curious about why other people or the CI didn't hit such crash.
FWIW, I'm hitting it on RISC-V:
| Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000008
| Oops [#1]
| Modules linked in: sch_fq_codel drm fuse drm_panel_orientation_quirks backlight
| CPU: 7 UID: 0 PID: 732 Comm: test_sockmap Not tainted 6.13.0-rc3-00017-gf44d154d6e3d #1
| Hardware name: riscv-virtio qemu/qemu, BIOS 2025.01-rc3-00042-gacab6e78aca7 01/01/2025
| epc : splice_to_socket+0x376/0x49a
| ra : splice_to_socket+0x37c/0x49a
| epc : ffffffff803d9ffc ra : ffffffff803da002 sp : ff20000001c3b8b0
| gp : ffffffff827aefa8 tp : ff60000083450040 t0 : ff6000008a12d001
| t1 : 0000100100001001 t2 : 0000000000000000 s0 : ff20000001c3bae0
| s1 : ffffffffffffefff a0 : ff6000008245e200 a1 : ff60000087dd0450
| a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
| a5 : 0000000000000000 a6 : ff20000001c3b450 a7 : ff6000008a12c004
| s2 : 000000000000000f s3 : ff6000008245e2d0 s4 : ff6000008245e280
| s5 : 0000000000000000 s6 : 0000000000000002 s7 : 0000000000001001
| s8 : 0000000000003001 s9 : 0000000000000002 s10: 0000000000000002
| s11: ff6000008245e200 t3 : ffffffff8001e78c t4 : 0000000000000000
| t5 : 0000000000000000 t6 : ff6000008869f230
| status: 0000000200000120 badaddr: 0000000000000008 cause: 000000000000000d
| [<ffffffff803d9ffc>] splice_to_socket+0x376/0x49a
| [<ffffffff803d8bc0>] direct_splice_actor+0x44/0x216
| [<ffffffff803d8532>] splice_direct_to_actor+0xb6/0x1e8
| [<ffffffff803d8780>] do_splice_direct+0x70/0xa2
| [<ffffffff80392e40>] do_sendfile+0x26e/0x2d4
| [<ffffffff803939d4>] __riscv_sys_sendfile64+0xf2/0x10e
| [<ffffffff80fdfb64>] do_trap_ecall_u+0x1f8/0x26c
| [<ffffffff80fedaee>] _new_vmalloc_restore_context_a0+0xc6/0xd2
| Code: c5d8 9e35 c590 8bb3 40db eb01 6998 b823 0005 856e (6718) 2d05
| ---[ end trace 0000000000000000 ]---
| Kernel panic - not syncing: Fatal exception
| SMP: stopping secondary CPUs
| ---[ end Kernel panic - not syncing: Fatal exception ]---
This is commit f44d154d6e3d ("Merge tag 'soc-fixes-6.13' of
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc").
(Yet to bisect!)
Björn
