| From ba993e785ae0ce3e45b2832165412d83c3a8daef Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 23 Jul 2019 16:50:20 +0100 |
| Subject: ceph: fix directories inode i_blkbits initialization |
| |
| From: Luis Henriques <lhenriques@suse.com> |
| |
| [ Upstream commit 750670341a24cb714e624e0fd7da30900ad93752 ] |
| |
| 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> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 a663b676d5661..2ad3f4ab4dcfa 100644 |
| --- a/fs/ceph/inode.c |
| +++ b/fs/ceph/inode.c |
| @@ -725,7 +725,12 @@ static int fill_inode(struct inode *inode, struct page *locked_page, |
| ci->i_version = le64_to_cpu(info->version); |
| inode->i_version++; |
| 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; |
| |
| if ((new_version || (new_issued & CEPH_CAP_AUTH_SHARED)) && |
| (issued & CEPH_CAP_AUTH_EXCL) == 0) { |
| -- |
| 2.20.1 |
| |
