From: Li Guifu <[email protected]> [ Upstream commit 99c787cfd2bd04926f1f553b30bd7dcea2caaba1 ]
During umount, f2fs_put_super() unregisters procfs entries after f2fs_destroy_segment_manager(), it may cause use-after-free issue when umount races with procfs accessing, fix it by relocating f2fs_unregister_sysfs(). [Chao Yu: change commit title/message a bit] Signed-off-by: Li Guifu <[email protected]> Reviewed-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- fs/f2fs/super.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 89319c3524061..990339c538b0a 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -782,6 +782,9 @@ static void f2fs_put_super(struct super_block *sb) struct f2fs_sb_info *sbi = F2FS_SB(sb); int i; + /* unregister procfs/sysfs entries in advance to avoid race case */ + f2fs_unregister_sysfs(sbi); + f2fs_quota_off_umount(sb); /* prevent remaining shrinker jobs */ @@ -834,8 +837,6 @@ static void f2fs_put_super(struct super_block *sb) kfree(sbi->ckpt); - f2fs_unregister_sysfs(sbi); - sb->s_fs_info = NULL; if (sbi->s_chksum_driver) crypto_free_shash(sbi->s_chksum_driver); -- 2.25.1

