mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-29 23:53:32 +00:00
Code Issues Releases Wiki Activity

nvmet: fix a NULL pointer dereference when tracing the flush command

Browse source 
When target side trace in turned on and flush command is issued from the
host it results in the following Oops.

[  856.789724] BUG: kernel NULL pointer dereference, address: 0000000000000068
[  856.790686] #PF: supervisor read access in kernel mode
[  856.791262] #PF: error_code(0x0000) - not-present page
[  856.791863] PGD 6d7110067 P4D 6d7110067 PUD 66f0ad067 PMD 0
[  856.792527] Oops: 0000 [#1] SMP NOPTI
[  856.792950] CPU: 15 PID: 7034 Comm: nvme Tainted: G           OE     5.9.0nvme-5.9+ #71
[  856.793790] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e3214
[  856.794956] RIP: 0010:trace_event_raw_event_nvmet_req_init+0x13e/0x170 [nvmet]
[  856.795734] Code: 41 5c 41 5d c3 31 d2 31 f6 e8 4e 9b b8 e0 e9 0e ff ff ff 49 8b 55 00 48 8b 38 8b 0
[  856.797740] RSP: 0018:ffffc90001be3a60 EFLAGS: 00010246
[  856.798375] RAX: 0000000000000000 RBX: ffff8887e7d2c01c RCX: 0000000000000000
[  856.799234] RDX: 0000000000000020 RSI: 0000000057e70ea2 RDI: ffff8887e7d2c034
[  856.800088] RBP: ffff88869f710578 R08: ffff888807500d40 R09: 00000000fffffffe
[  856.800951] R10: 0000000064c66670 R11: 00000000ef955201 R12: ffff8887e7d2c034
[  856.801807] R13: ffff88869f7105c8 R14: 0000000000000040 R15: ffff88869f710440
[  856.802667] FS:  00007f6a22bd8780(0000) GS:ffff888813a00000(0000) knlGS:0000000000000000
[  856.803635] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  856.804367] CR2: 0000000000000068 CR3: 00000006d73e0000 CR4: 00000000003506e0
[  856.805283] Call Trace:
[  856.805613]  nvmet_req_init+0x27c/0x480 [nvmet]
[  856.806200]  nvme_loop_queue_rq+0xcb/0x1d0 [nvme_loop]
[  856.806862]  blk_mq_dispatch_rq_list+0x123/0x7b0
[  856.807459]  ? kvm_sched_clock_read+0x14/0x30
[  856.808025]  __blk_mq_sched_dispatch_requests+0xc7/0x170
[  856.808708]  blk_mq_sched_dispatch_requests+0x30/0x60
[  856.809372]  __blk_mq_run_hw_queue+0x70/0x100
[  856.809935]  __blk_mq_delay_run_hw_queue+0x156/0x170
[  856.810574]  blk_mq_run_hw_queue+0x86/0xe0
[  856.811104]  blk_mq_sched_insert_request+0xef/0x160
[  856.811733]  blk_execute_rq+0x69/0xc0
[  856.812212]  ? blk_mq_rq_ctx_init+0xd0/0x230
[  856.812784]  nvme_execute_passthru_rq+0x57/0x130 [nvme_core]
[  856.813461]  nvme_submit_user_cmd+0xeb/0x300 [nvme_core]
[  856.814099]  nvme_user_cmd.isra.82+0x11e/0x1a0 [nvme_core]
[  856.814752]  blkdev_ioctl+0x1dc/0x2c0
[  856.815197]  block_ioctl+0x3f/0x50
[  856.815606]  __x64_sys_ioctl+0x84/0xc0
[  856.816074]  do_syscall_64+0x33/0x40
[  856.816533]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  856.817168] RIP: 0033:0x7f6a222ed107
[  856.817617] Code: 44 00 00 48 8b 05 81 cd 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 8
[  856.819901] RSP: 002b:00007ffca848f058 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  856.820846] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f6a222ed107
[  856.821726] RDX: 00007ffca848f060 RSI: 00000000c0484e43 RDI: 0000000000000003
[  856.822603] RBP: 0000000000000003 R08: 000000000000003f R09: 0000000000000005
[  856.823478] R10: 00007ffca848ece0 R11: 0000000000000202 R12: 00007ffca84912d3
[  856.824359] R13: 00007ffca848f4d0 R14: 0000000000000002 R15: 000000000067e900
[  856.825236] Modules linked in: nvme_loop(OE) nvmet(OE) nvme_fabrics(OE) null_blk nvme(OE) nvme_corel

Move the nvmet_req_init() tracepoint after we parse the command in
nvmet_req_init() so that we can get rid of the duplicate
nvmet_find_namespace() call.
Rename __assign_disk_name() ->  __assign_req_name(). Now that we call
tracepoint after parsing the command simplify the newly added
__assign_req_name() which fixes this bug.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Chaitanya Kulkarni 2020-10-22 16:58:21 -07:00 committed by Christoph Hellwig
parent ac9b820e71
commit 3c3751f2da
2 changed files with 9 additions and 16 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
drivers/nvme/target/core.c
View file

@ -907,8 +907,6 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
req->error_loc = NVMET_NO_ERROR_LOC;
req->error_slba = 0;
trace_nvmet_req_init(req, req->cmd);
/* no support for fused commands yet */
if (unlikely(flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND))) {
req->error_loc = offsetof(struct nvme_common_command, flags);
@ -938,6 +936,8 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
if (status)
goto fail;
trace_nvmet_req_init(req, req->cmd);
if (unlikely(!percpu_ref_tryget_live(&sq->ref))) {
status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
goto fail;

21
drivers/nvme/target/trace.h
View file

@ -46,19 +46,12 @@ static inline struct nvmet_ctrl *nvmet_req_to_ctrl(struct nvmet_req *req)
return req->sq->ctrl;
}
static inline void __assign_disk_name(char *name, struct nvmet_req *req,
bool init)
static inline void __assign_req_name(char *name, struct nvmet_req *req)
{
struct nvmet_ctrl *ctrl = nvmet_req_to_ctrl(req);
struct nvmet_ns *ns;
if ((init && req->sq->qid) || (!init && req->cq->qid)) {
ns = nvmet_find_namespace(ctrl, req->cmd->rw.nsid);
strncpy(name, ns->device_path, DISK_NAME_LEN);
return;
}
memset(name, 0, DISK_NAME_LEN);
if (req->ns)
strncpy(name, req->ns->device_path, DISK_NAME_LEN);
else
memset(name, 0, DISK_NAME_LEN);
}
#endif
@ -81,7 +74,7 @@ TRACE_EVENT(nvmet_req_init,
TP_fast_assign(
__entry->cmd = cmd;
__entry->ctrl = nvmet_req_to_ctrl(req);
__assign_disk_name(__entry->disk, req, true);
__assign_req_name(__entry->disk, req);
__entry->qid = req->sq->qid;
__entry->cid = cmd->common.command_id;
__entry->opcode = cmd->common.opcode;
@ -121,7 +114,7 @@ TRACE_EVENT(nvmet_req_complete,
__entry->cid = req->cqe->command_id;
__entry->result = le64_to_cpu(req->cqe->result.u64);
__entry->status = le16_to_cpu(req->cqe->status) >> 1;
__assign_disk_name(__entry->disk, req, false);
__assign_req_name(__entry->disk, req);
),
TP_printk("nvmet%s: %sqid=%d, cmdid=%u, res=%#llx, status=%#x",
__print_ctrl_name(__entry->ctrl),