From 2ac6761657cf7c01ef522e7c67c9489d13f78499 Mon Sep 17 00:00:00 2001 From: Zhiguo Niu Date: Wed, 28 Feb 2024 19:59:54 +0800 Subject: [PATCH] f2fs: fix to do sanity check in update_sit_entry BugLink: https://bugs.launchpad.net/bugs/2084005 [ 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 Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- 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 e03f283bf274..2505e33e5964 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -2400,6 +2400,8 @@ 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; @@ -3483,8 +3485,7 @@ 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 the current segment is full, flush it out and replace it with a