This is a note to let you know that I've just added the patch titled f2fs: fix to do sanity check in update_sit_entry to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: f2fs-fix-to-do-sanity-check-in-update_sit_entry.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 0bb70e209ab70aa47ae26c385612cb453b835ba1 Author: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx> Date: Wed Feb 28 19:59:54 2024 +0800 f2fs: fix to do sanity check in update_sit_entry [ Upstream commit 36959d18c3cf09b3c12157c6950e18652067de77 ] If GET_SEGNO return NULL_SEGNO for some unecpected case, update_sit_entry will access invalid memory address, cause system crash. It is better to do sanity check about GET_SEGNO just like update_segment_mtime & locate_dirty_segment. Also remove some redundant judgment code. Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx> Reviewed-by: Chao Yu <chao@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index e43b57755a7fe..da37e2b8a0ec7 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -2131,6 +2131,8 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) #endif segno = GET_SEGNO(sbi, blkaddr); + if (segno == NULL_SEGNO) + return; se = get_seg_entry(sbi, segno); new_vblocks = se->valid_blocks + del; @@ -3113,8 +3115,7 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, * since SSR needs latest valid block information. */ update_sit_entry(sbi, *new_blkaddr, 1); - if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO) - update_sit_entry(sbi, old_blkaddr, -1); + update_sit_entry(sbi, old_blkaddr, -1); if (!__has_curseg_space(sbi, type)) sit_i->s_ops->allocate_segment(sbi, type, false);