From: Wenjie Qi qwjhust@gmail.com

mainline inclusion from mainline-v6.9-rc1 commit c2034ef6192a65a986a45c2aa2ed05824fdc0e9f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9HKBD CVE: CVE-2024-26871

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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BUG: kernel NULL pointer dereference, address: 0000000000000014 RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs] Call Trace: <TASK> ? show_regs+0x6e/0x80 ? __die+0x29/0x70 ? page_fault_oops+0x154/0x4a0 ? prb_read_valid+0x20/0x30 ? __irq_work_queue_local+0x39/0xd0 ? irq_work_queue+0x36/0x70 ? do_user_addr_fault+0x314/0x6c0 ? exc_page_fault+0x7d/0x190 ? asm_exc_page_fault+0x2b/0x30 ? f2fs_submit_page_write+0x6cf/0x780 [f2fs] ? f2fs_submit_page_write+0x736/0x780 [f2fs] do_write_page+0x50/0x170 [f2fs] f2fs_outplace_write_data+0x61/0xb0 [f2fs] f2fs_do_write_data_page+0x3f8/0x660 [f2fs] f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs] f2fs_write_cache_pages+0x3da/0xbe0 [f2fs] ... It is possible that other threads have added this fio to io->bio and submitted the io->bio before entering f2fs_submit_page_write(). At this point io->bio = NULL. If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true, then an NULL pointer dereference error occurs at bio_get(io->bio). The original code for determining zone end was after "out:", which would have missed some fio who is zone end. I've moved this code before "skip:" to make sure it's done for each fio.

Fixes: e067dc3c6b9c ("f2fs: maintain six open zones for zoned devices") Signed-off-by: Wenjie Qi qwjhust@gmail.com Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Yifan Qiao qiaoyifan4@huawei.com --- fs/f2fs/data.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index f5f33926acf8..8ab19498dcd7 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1080,10 +1080,6 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio) io->last_block_in_bio = fio->new_blkaddr;

trace_f2fs_submit_page_write(fio->page, fio); -skip: - if (fio->in_list) - goto next; -out: #ifdef CONFIG_BLK_DEV_ZONED if (f2fs_sb_has_blkzoned(sbi) && btype < META && is_end_zone_blkaddr(sbi, fio->new_blkaddr)) { @@ -1096,6 +1092,10 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio) __submit_merged_bio(io); } #endif +skip: + if (fio->in_list) + goto next; +out: if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) || !f2fs_is_checkpoint_ready(sbi)) __submit_merged_bio(io);