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authorEric Sandeen <sandeen@redhat.com>2018-08-16 21:44:02 -0500
committerJan Kara <jack@suse.cz>2018-08-21 11:37:41 +0200
commit09a4e0be5826aa66c4ce9954841f110ffe63ef4f (patch)
tree9d4b485a463591aaa53757d5076c3f4ac2bb2950 /fs/isofs
parentd3bc0fa8411c35194f99046157e2e26fe60e1d91 (diff)
isofs: reject hardware sector size > 2048 bytes
The largest block size supported by isofs is ISOFS_BLOCK_SIZE (2048), but isofs_fill_super calls sb_min_blocksize and sets the blocksize to the device's logical block size if it's larger than what we ended up with after option parsing. If for some reason we try to mount a hard 4k device as an isofs filesystem, we'll set opt.blocksize to 4096, and when we try to read the superblock we found via: block = iso_blknum << (ISOFS_BLOCK_BITS - s->s_blocksize_bits) with s_blocksize_bits greater than ISOFS_BLOCK_BITS, we'll have a negative shift and the bread will fail somewhat cryptically: isofs_fill_super: bread failed, dev=sda, iso_blknum=17, block=-2147483648 It seems best to just catch and clearly reject mounts of such a device. Reported-by: Bryan Gurney <bgurney@redhat.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/isofs')
-rw-r--r--fs/isofs/inode.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index ec3fba7d492f..488a9e7f8f66 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -24,6 +24,7 @@
#include <linux/mpage.h>
#include <linux/user_namespace.h>
#include <linux/seq_file.h>
+#include <linux/blkdev.h>
#include "isofs.h"
#include "zisofs.h"
@@ -653,6 +654,12 @@ static int isofs_fill_super(struct super_block *s, void *data, int silent)
/*
* What if bugger tells us to go beyond page size?
*/
+ if (bdev_logical_block_size(s->s_bdev) > 2048) {
+ printk(KERN_WARNING
+ "ISOFS: unsupported/invalid hardware sector size %d\n",
+ bdev_logical_block_size(s->s_bdev));
+ goto out_freesbi;
+ }
opt.blocksize = sb_min_blocksize(s, opt.blocksize);
sbi->s_high_sierra = 0; /* default is iso9660 */