[PATCH AUTOSEL 5.7 46/61] f2fs: fix use-after-free issue
From: Sasha Levin <sashal@kernel.org>
Date: 2020-08-21 17:15:28
Also in:
linux-f2fs-devel, lkml
Subsystem:
f2fs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Jaegeuk Kim, Chao Yu, Alexander Viro, Christian Brauner, Linus Torvalds
From: Li Guifu <redacted> [ 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 <redacted> Reviewed-by: Chao Yu <redacted> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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 4696c9cb47a5f..194ac4941584e 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c@@ -1145,6 +1145,9 @@ static void f2fs_put_super(struct super_block *sb) int i; bool dropped; + /* unregister procfs/sysfs entries in advance to avoid race case */ + f2fs_unregister_sysfs(sbi); + f2fs_quota_off_umount(sb); /* prevent remaining shrinker jobs */
@@ -1210,8 +1213,6 @@ static void f2fs_put_super(struct super_block *sb) kvfree(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