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authorDavid Sterba <dsterba@suse.com>2015-11-30 17:27:06 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-25 12:01:15 -0800
commitc57e49b50bc5ab5089bc1295bab9106925033c40 (patch)
tree13ff2e3557d39e454f8cc66a4b35a0b1af27c067 /fs/btrfs
parentbbfe21c87bd0f529d19f077051a52d779c785c6c (diff)
btrfs: handle invalid num_stripes in sys_array
commit f5cdedd73fa71b74dcc42f2a11a5735d89ce7c4f upstream. We can handle the special case of num_stripes == 0 directly inside btrfs_read_sys_array. The BUG_ON in btrfs_chunk_item_size is there to catch other unhandled cases where we fail to validate external data. A crafted or corrupted image crashes at mount time: BTRFS: device fsid 9006933e-2a9a-44f0-917f-514252aeec2c devid 1 transid 7 /dev/loop0 BTRFS info (device loop0): disk space caching is enabled BUG: failure at fs/btrfs/ctree.h:337/btrfs_chunk_item_size()! Kernel panic - not syncing: BUG! CPU: 0 PID: 313 Comm: mount Not tainted 4.2.5-00657-ge047887-dirty #25 Stack: 637af890 60062489 602aeb2e 604192ba 60387961 00000011 637af8a0 6038a835 637af9c0 6038776b 634ef32b 00000000 Call Trace: [<6001c86d>] show_stack+0xfe/0x15b [<6038a835>] dump_stack+0x2a/0x2c [<6038776b>] panic+0x13e/0x2b3 [<6020f099>] btrfs_read_sys_array+0x25d/0x2ff [<601cfbbe>] open_ctree+0x192d/0x27af [<6019c2c1>] btrfs_mount+0x8f5/0xb9a [<600bc9a7>] mount_fs+0x11/0xf3 [<600d5167>] vfs_kern_mount+0x75/0x11a [<6019bcb0>] btrfs_mount+0x2e4/0xb9a [<600bc9a7>] mount_fs+0x11/0xf3 [<600d5167>] vfs_kern_mount+0x75/0x11a [<600d710b>] do_mount+0xa35/0xbc9 [<600d7557>] SyS_mount+0x95/0xc8 [<6001e884>] handle_syscall+0x6b/0x8e Reported-by: Jiri Slaby <jslaby@suse.com> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/volumes.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a23399e8e3ab..a5094b8ca281 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6512,6 +6512,14 @@ int btrfs_read_sys_array(struct btrfs_root *root)
goto out_short_read;
num_stripes = btrfs_chunk_num_stripes(sb, chunk);
+ if (!num_stripes) {
+ printk(KERN_ERR
+ "BTRFS: invalid number of stripes %u in sys_array at offset %u\n",
+ num_stripes, cur_offset);
+ ret = -EIO;
+ break;
+ }
+
len = btrfs_chunk_item_size(num_stripes);
if (cur_offset + len > array_size)
goto out_short_read;