Re: [f2fs-dev] [PATCH v2] f2fs: fix null pointer panic in tracepoint in __replace_atomic_write_block

[Chao Yu]

On 2023/4/4 0:54, Jaegeuk Kim wrote:
> We got a kernel panic if old_addr is NULL.
>
> https://bugzilla.kernel.org/show_bug.cgi?id=217266
>
> BUG: kernel NULL pointer dereference, address: 0000000000000000
>   Call Trace:
>    <TASK>
>    f2fs_commit_atomic_write+0x619/0x990 [f2fs a1b985b80f5babd6f3ea778384908880812bfa43]
>    __f2fs_ioctl+0xd8e/0x4080 [f2fs a1b985b80f5babd6f3ea778384908880812bfa43]
>    ? vfs_write+0x2ae/0x3f0
>    ? vfs_write+0x2ae/0x3f0
>    __x64_sys_ioctl+0x91/0xd0
>    do_syscall_64+0x5c/0x90
>    entry_SYSCALL_64_after_hwframe+0x72/0xdc
>   RIP: 0033:0x7f69095fe53f
>
> Fixes: 2f3a9ae990a7 ("f2fs: introduce trace_f2fs_replace_atomic_write_block")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

Thanks for fixing this. :)

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,