Fix use after free in get_tree_bdev()
Commit 6fcf0c72, a fix to get_tree_bdev() put a missing blkdev_put() in the wrong place, before a warnf() that displays the bdev under consideration rather after it. This results in a silent lockup in printk("%pg") called via warnf() from get_tree_bdev() under some circumstances when there's a race with the blockdev being frozen. This can be caused by xfstests/tests/generic/085 in combination with Lukas Czerner's ext4 mount API conversion patchset. It looks like it ought to occur with other users of get_tree_bdev() such as XFS, but apparently doesn't. Fix this by switching the order of the lines. Fixes: 6fcf0c72 ("vfs: add missing blkdev_put() in get_tree_bdev()") Reported-by:Lukas Czerner <lczerner@redhat.com> Signed-off-by:
David Howells <dhowells@redhat.com> cc: Ian Kent <raven@themaw.net> cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
parent
edb98d16
Please register or sign in to comment