| From foo@baz Mon Apr 9 17:09:24 CEST 2018 |
| From: Dmitry Monakhov <dmonakhov@openvz.org> |
| Date: Wed, 10 May 2017 19:20:44 +0400 |
| Subject: bio-integrity: Do not allocate integrity context for bio w/o data |
| |
| From: Dmitry Monakhov <dmonakhov@openvz.org> |
| |
| |
| [ Upstream commit 3116a23bb30272d74ea81baf5d0ee23f602dd15b ] |
| |
| If bio has no data, such as ones from blkdev_issue_flush(), |
| then we have nothing to protect. |
| |
| This patch prevent bugon like follows: |
| |
| kfree_debugcheck: out of range ptr ac1fa1d106742a5ah |
| kernel BUG at mm/slab.c:2773! |
| invalid opcode: 0000 [#1] SMP |
| Modules linked in: bcache |
| CPU: 0 PID: 4428 Comm: xfs_io Tainted: G W 4.11.0-rc4-ext4-00041-g2ef0043-dirty #43 |
| Hardware name: Virtuozzo KVM, BIOS seabios-1.7.5-11.vz7.4 04/01/2014 |
| task: ffff880137786440 task.stack: ffffc90000ba8000 |
| RIP: 0010:kfree_debugcheck+0x25/0x2a |
| RSP: 0018:ffffc90000babde0 EFLAGS: 00010082 |
| RAX: 0000000000000034 RBX: ac1fa1d106742a5a RCX: 0000000000000007 |
| RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88013f3ccb40 |
| RBP: ffffc90000babde8 R08: 0000000000000000 R09: 0000000000000000 |
| R10: 00000000fcb76420 R11: 00000000725172ed R12: 0000000000000282 |
| R13: ffffffff8150e766 R14: ffff88013a145e00 R15: 0000000000000001 |
| FS: 00007fb09384bf40(0000) GS:ffff88013f200000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 00007fd0172f9e40 CR3: 0000000137fa9000 CR4: 00000000000006f0 |
| Call Trace: |
| kfree+0xc8/0x1b3 |
| bio_integrity_free+0xc3/0x16b |
| bio_free+0x25/0x66 |
| bio_put+0x14/0x26 |
| blkdev_issue_flush+0x7a/0x85 |
| blkdev_fsync+0x35/0x42 |
| vfs_fsync_range+0x8e/0x9f |
| vfs_fsync+0x1c/0x1e |
| do_fsync+0x31/0x4a |
| SyS_fsync+0x10/0x14 |
| entry_SYSCALL_64_fastpath+0x1f/0xc2 |
| |
| Reviewed-by: Christoph Hellwig <hch@lst.de> |
| Reviewed-by: Hannes Reinecke <hare@suse.com> |
| Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> |
| Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> |
| Signed-off-by: Jens Axboe <axboe@fb.com> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| block/bio-integrity.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/block/bio-integrity.c |
| +++ b/block/bio-integrity.c |
| @@ -175,6 +175,9 @@ bool bio_integrity_enabled(struct bio *b |
| if (!bio_is_rw(bio)) |
| return false; |
| |
| + if (!bio_sectors(bio)) |
| + return false; |
| + |
| /* Already protected? */ |
| if (bio_integrity(bio)) |
| return false; |