From: Luis Henriques <lhenriques@suse.com>
Date: Tue, 23 Jul 2019 16:50:20 +0100
Subject: ceph: fix directories inode i_blkbits initialization
Git-commit: 750670341a24cb714e624e0fd7da30900ad93752
Patch-mainline: v5.4-rc1
References: bsc#1153717
When filling an inode with info from the MDS, i_blkbits is being
initialized using fl_stripe_unit, which contains the stripe unit in
bytes. Unfortunately, this doesn't make sense for directories as they
have fl_stripe_unit set to '0'. This means that i_blkbits will be set
to 0xff, causing an UBSAN undefined behaviour in i_blocksize():
UBSAN: Undefined behaviour in ./include/linux/fs.h:731:12
shift exponent 255 is too large for 32-bit type 'int'
Fix this by initializing i_blkbits to CEPH_BLOCK_SHIFT if fl_stripe_unit
is zero.
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---
fs/ceph/inode.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 18500edefc56..3b537e7038c7 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -801,7 +801,12 @@ static int fill_inode(struct inode *inode, struct page *locked_page,
/* update inode */
inode->i_rdev = le32_to_cpu(info->rdev);
- inode->i_blkbits = fls(le32_to_cpu(info->layout.fl_stripe_unit)) - 1;
+ /* directories have fl_stripe_unit set to zero */
+ if (le32_to_cpu(info->layout.fl_stripe_unit))
+ inode->i_blkbits =
+ fls(le32_to_cpu(info->layout.fl_stripe_unit)) - 1;
+ else
+ inode->i_blkbits = CEPH_BLOCK_SHIFT;
__ceph_update_quota(ci, iinfo->max_bytes, iinfo->max_files);