From 78ba94e80f840537fae75e180bf85e7431f5b09c Mon Sep 17 00:00:00 2001 From: Luis Henriques Date: Tue, 23 Jul 2019 16:50:20 +0100 Subject: [PATCH] ceph: fix directories inode i_blkbits initialization [ 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 Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- 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 a663b676d566..2ad3f4ab4dcf 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) { -- 2.11.0