4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx> [ 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> --- fs/f2fs/segment.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 34090edc8ce25..6750cda692cc3 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -2018,6 +2018,8 @@ 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; @@ -2935,8 +2937,7 @@ 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); -- 2.43.0
