5.4-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
[ Upstream commit 57e9d49c54528c49b8bffe6d99d782ea051ea534 ]
There appears to be a race between silly-rename files being created/removed and various userspace tools iterating over the contents of a directory, leading to such errors as:
find: './kernel/.tmp_cpio_dir/include/dt-bindings/reset/.__afs2080': No such file or directory tar: ./include/linux/greybus/.__afs3C95: File removed before we read it
when building a kernel.
Fix afs_readdir() so that it doesn't return .__afsXXXX silly-rename files to userspace. This doesn't stop them being looked up directly by name as we need to be able to look them up from within the kernel as part of the silly-rename algorithm.
Fixes: 79ddbfa500b3 ("afs: Implement sillyrename for unlink and rename") Signed-off-by: David Howells dhowells@redhat.com cc: Marc Dionne marc.dionne@auristor.com cc: linux-afs@lists.infradead.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/afs/dir.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 43f5b972fcea..8bed9df09230 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -421,6 +421,14 @@ static int afs_dir_iterate_block(struct afs_vnode *dvnode, continue; }
+ /* Don't expose silly rename entries to userspace. */ + if (nlen > 6 && + dire->u.name[0] == '.' && + ctx->actor != afs_lookup_filldir && + ctx->actor != afs_lookup_one_filldir && + memcmp(dire->u.name, ".__afs", 6) == 0) + continue; + /* found the next entry */ if (!dir_emit(ctx, dire->u.name, nlen, ntohl(dire->u.vnode),