This is a note to let you know that I've just added the patch titled
fuse: fix root lookup with nonzero generation
to the 6.8-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:
fuse-fix-root-lookup-with-nonzero-generation.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b3ffa2f2fa3226b313f8dd8ac8e648b8417ed923
Author: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Date: Wed Feb 28 16:50:49 2024 +0100
fuse: fix root lookup with nonzero generation
[ Upstream commit 68ca1b49e430f6534d0774a94147a823e3b8b26e ]
The root inode has a fixed nodeid and generation (1, 0).
Prior to the commit 15db16837a35 ("fuse: fix illegal access to inode with
reused nodeid") generation number on lookup was ignored. After this commit
lookup with the wrong generation number resulted in the inode being
unhashed. This is correct for non-root inodes, but replacing the root
inode is wrong and results in weird behavior.
Fix by reverting to the old behavior if ignoring the generation for the
root inode, but issuing a warning in dmesg.
Reported-by: Antonio SJ Musumeci <trapexit@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/CAOQ4uxhek5ytdN8Yz2tNEOg5ea4NkBb4nk0FGPjPk_9nz-VG3g@xxxxxxxxxxxxxx/
Fixes: 15db16837a35 ("fuse: fix illegal access to inode with reused nodeid")
Cc: <stable@xxxxxxxxxxxxxxx> # v5.14
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index d3bc463d9da76..9307bb4393b8f 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -391,6 +391,10 @@ int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name
err = -EIO;
if (fuse_invalid_attr(&outarg->attr))
goto out_put_forget;
+ if (outarg->nodeid == FUSE_ROOT_ID && outarg->generation != 0) {
+ pr_warn_once("root generation should be zero\n");
+ outarg->generation = 0;
+ }
*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
&outarg->attr, ATTR_TIMEOUT(outarg),
