Jens, can you pick this up for 4.12? On Wed, May 10, 2017 at 07:20:44PM +0400, Dmitry Monakhov wrote: > 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@xxxxxx> > Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> > Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> > Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> > --- > block/bio-integrity.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/block/bio-integrity.c b/block/bio-integrity.c > index 5384713..b5009a8 100644 > --- a/block/bio-integrity.c > +++ b/block/bio-integrity.c > @@ -175,6 +175,9 @@ bool bio_integrity_enabled(struct bio *bio) > if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE) > return false; > > + if (!bio_sectors(bio)) > + return false; > + > /* Already protected? */ > if (bio_integrity(bio)) > return false; > -- > 2.9.3 > ---end quoted text---
