The ioc->sgl[i].iov_len value is supplied by the ioctl caller, and can be zero in some cases. Assume that's valid and continue without error. Fixes: [ 69.162538] ------------[ cut here ]------------ [ 69.162806] kernel BUG at /build/buildd/linux-2.6.32/lib/swiotlb.c:368! [ 69.163134] invalid opcode: 0000 [#1] SMP [ 69.163570] last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map [ 69.163975] CPU 0 [ 69.164227] Modules linked in: fbcon tileblit font bitblit softcursor vga16fb vgastate ioatdma radeon ttm drm_kms_helper shpchp drm i2c_algo_bit lp parport floppy pata_jmicron megaraid_sas igb dca [ 69.167419] Pid: 1206, comm: smartctl Tainted: G W 2.6.32-25-server #45-Ubuntu X8DTN [ 69.167843] RIP: 0010:[<ffffffff812c4dc5>] [<ffffffff812c4dc5>] map_single+0x255/0x260 [ 69.168370] RSP: 0018:ffff88081c0ebc58 EFLAGS: 00010246 [ 69.168655] RAX: 000000000003bffc RBX: 00000000ffffffff RCX: 0000000000000002 [ 69.169000] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88001dffe000 [ 69.169346] RBP: ffff88081c0ebcb8 R08: 0000000000000000 R09: ffff880000030840 [ 69.169691] R10: 0000000000100000 R11: 0000000000000000 R12: 0000000000000000 [ 69.170036] R13: 00000000ffffffff R14: 0000000000000001 R15: 0000000000200000 [ 69.170382] FS: 00007fb8de189720(0000) GS:ffff88001de00000(0000) knlGS:0000000000000000 [ 69.170794] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 69.171094] CR2: 00007fb8dd59237c CR3: 000000081a790000 CR4: 00000000000006f0 [ 69.171439] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 69.171784] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 69.172130] Process smartctl (pid: 1206, threadinfo ffff88081c0ea000, task ffff88081a760000) [ 69.194513] Stack: [ 69.205788] 0000000000000034 00000002817e3390 0000000000000000 ffff88081c0ebe00 [ 69.217739] <0> 0000000000000000 000000000003bffc 0000000000000000 0000000000000000 [ 69.241250] <0> 0000000000000000 00000000ffffffff ffff88081c5b4080 ffff88081c0ebe00 [ 69.277310] Call Trace: [ 69.289278] [<ffffffff812c52ac>] swiotlb_alloc_coherent+0xec/0x130 [ 69.301118] [<ffffffff81038b31>] x86_swiotlb_alloc_coherent+0x61/0x70 [ 69.313045] [<ffffffffa002d0ce>] megasas_mgmt_fw_ioctl+0x1ae/0x690 [megaraid_sas] [ 69.336399] [<ffffffffa002d748>] megasas_mgmt_ioctl_fw+0x198/0x240 [megaraid_sas] [ 69.359346] [<ffffffffa002f695>] megasas_mgmt_ioctl+0x35/0x50 [megaraid_sas] [ 69.370902] [<ffffffff81153b12>] vfs_ioctl+0x22/0xa0 [ 69.382322] [<ffffffff8115da2a>] ? alloc_fd+0x10a/0x150 [ 69.393622] [<ffffffff81153cb1>] do_vfs_ioctl+0x81/0x410 [ 69.404696] [<ffffffff8155cc13>] ? do_page_fault+0x153/0x3b0 [ 69.415761] [<ffffffff811540c1>] sys_ioctl+0x81/0xa0 [ 69.426640] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b [ 69.437491] Code: fe ff ff 48 8b 3d 74 38 76 00 41 bf 00 00 20 00 e8 51 f5 d7 ff 83 e0 ff 48 05 ff 07 00 00 48 c1 e8 0b 48 89 45 c8 e9 13 fe ff ff <0f> 0b eb fe 0f 1f 80 00 00 00 00 55 48 89 e5 48 83 ec 20 4c 89 [ 69.478216] RIP [<ffffffff812c4dc5>] map_single+0x255/0x260 [ 69.489668] RSP <ffff88081c0ebc58> [ 69.500975] ---[ end trace 6a2181b634e2abc7 ]--- Reported-by: Bokhan Artem <aptem@xxxxxx> Signed-off-by: BjÃrn Mork <bjorn@xxxxxxx> Cc: stable@xxxxxxxxxx --- drivers/scsi/megaraid/megaraid_sas.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c index eb29d50..72713c5 100644 --- a/drivers/scsi/megaraid/megaraid_sas.c +++ b/drivers/scsi/megaraid/megaraid_sas.c @@ -4359,6 +4359,11 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance, * For each user buffer, create a mirror buffer and copy in */ for (i = 0; i < ioc->sge_count; i++) { + if (ioc->sgl[i].iov_len == 0) { + kbuff_arr[i] = NULL; + continue; + } + kbuff_arr[i] = dma_alloc_coherent(&instance->pdev->dev, ioc->sgl[i].iov_len, &buf_handle, GFP_KERNEL); -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html