This is a note to let you know that I've just added the patch titled f2fs: compress: fix to disallow enabling compress on non-empty file to the 5.9-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-compress-fix-to-disallow-enabling-compress-on-n.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2b7feb84b0ebbf4b7b45f93be6903f3df4ea43da Author: Chao Yu <yuchao0@xxxxxxxxxx> Date: Fri Sep 18 11:03:49 2020 +0800 f2fs: compress: fix to disallow enabling compress on non-empty file [ Upstream commit 519a5a2f37b850f4eb86674a10d143088670a390 ] Compressed inode and normal inode has different layout, so we should disallow enabling compress on non-empty file to avoid race condition during inode .i_addr array parsing and updating. Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx> [Jaegeuk Kim: Fix missing condition] Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 8a422400e824d..4ec10256dc67f 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1836,6 +1836,8 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask) if (iflags & F2FS_COMPR_FL) { if (!f2fs_may_compress(inode)) return -EINVAL; + if (S_ISREG(inode->i_mode) && inode->i_size) + return -EINVAL; set_compress_context(inode); }