* [PATCH v2 1/1] RDMA/cma: Fix WARNING in res_to_rt
@ 2026-08-10 22:01 Zhu Yanjun
2026-08-10 23:59 ` Zhu Yanjun
0 siblings, 1 reply; 2+ messages in thread
From: Zhu Yanjun @ 2026-08-10 22:01 UTC (permalink / raw)
To: jgg, leon, linux-rdma, yanjun.zhu; +Cc: syzbot+72eddfbadda3e3928e72
syzbot reported a WARN_ON(!res->dev) in res_to_rt() triggered via
addr_handler() during asynchronous address resolution:
"
WARNING: drivers/infiniband/core/restrack.c:138 at res_to_rt+0x1c4/0x230
CPU#1: kworker/u8:4/59
Modules linked in:
CPU: 1 UID: 0 PID: 59 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Compute Engine, BIOS Google 07/24/2026
Workqueue: ib_addr process_one_req
RIP: 0010:res_to_rt+0x1c4/0x230 drivers/infiniband/core/restrack.c:138
RSP: 0018:ffffc9000201f850 EFLAGS: 00010293
RAX: ffffffff88d00ce5 RBX: ffff88807f0fd4f8 RCX: ffff88801e6e0000
RDX: 0000000000000000 RSI: ffffffff8fd996f0 RDI: 0000000000000003
RBP: 0000000000000000 R08: ffff88801e6e0000 R09: 000000000000000a
R10: 0000000000000009 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff1100fe1fa9f R14: 0000000000000000 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff888125012000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00001d559c3d2000 CR3: 0000000077c4c000 CR4: 00000000003526f0
Call Trace:
<TASK>
rdma_restrack_add+0x5a/0x8a0 drivers/infiniband/core/restrack.c:236
addr_handler+0x41a/0x5a0 drivers/infiniband/core/cma.c:3534
process_one_req+0x2eb/0x540 drivers/infiniband/core/addr.c:624
process_one_work kernel/workqueue.c:3375 [inline]
process_scheduled_works+0xc4e/0x1630 kernel/workqueue.c:3458
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3539
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
"
In addr_handler(), cma_acquire_dev_by_src_ip() is called to populate
id_priv->cma_dev and bind the associated ib_device to id_priv->id.device.
If cma_acquire_dev_by_src_ip() returns an error (non-zero status), the ID
remains unassociated with any RDMA device.
Previously, rdma_restrack_add(&id_priv->res) was invoked unconditionally
even when cma_acquire_dev_by_src_ip() failed, passing a resource with a
NULL dev pointer and triggering the WARN_ON assertion in res_to_rt().
Fix this by only adding the resource to restrack when acquiring the device
succeeds.
Reported-by: syzbot+72eddfbadda3e3928e72@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=72eddfbadda3e3928e72
Tested-by: syzbot+72eddfbadda3e3928e72@syzkaller.appspotmail.com
Fixes: cb5cd0ea4eb3 ("RDMA/core: Add CM to restrack after successful attachment to a device")
Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
---
V1 -> V2: Follow Jason's advice to use if/else to handle this problem.
---
drivers/infiniband/core/cma.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index cc24fddf9aaa..73170b15fc3d 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3528,10 +3528,12 @@ static void addr_handler(int status, struct sockaddr *src_addr,
memcpy(addr, src_addr, rdma_addr_size(src_addr));
if (!status && !id_priv->cma_dev) {
status = cma_acquire_dev_by_src_ip(id_priv);
- if (status)
+ if (status) {
pr_debug_ratelimited("RDMA CM: ADDR_ERROR: failed to acquire device. status %d\n",
status);
- rdma_restrack_add(&id_priv->res);
+ } else {
+ rdma_restrack_add(&id_priv->res);
+ }
} else if (status) {
pr_debug_ratelimited("RDMA CM: ADDR_ERROR: failed to resolve IP. status %d\n", status);
}
--
2.43.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2 1/1] RDMA/cma: Fix WARNING in res_to_rt
2026-08-10 22:01 [PATCH v2 1/1] RDMA/cma: Fix WARNING in res_to_rt Zhu Yanjun
@ 2026-08-10 23:59 ` Zhu Yanjun
0 siblings, 0 replies; 2+ messages in thread
From: Zhu Yanjun @ 2026-08-10 23:59 UTC (permalink / raw)
To: jgg, leon, linux-rdma; +Cc: syzbot+72eddfbadda3e3928e72
在 2026/8/10 15:01, Zhu Yanjun 写道:
> syzbot reported a WARN_ON(!res->dev) in res_to_rt() triggered via
> addr_handler() during asynchronous address resolution:
>
> "
> WARNING: drivers/infiniband/core/restrack.c:138 at res_to_rt+0x1c4/0x230
> CPU#1: kworker/u8:4/59
> Modules linked in:
> CPU: 1 UID: 0 PID: 59 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: Google Compute Engine, BIOS Google 07/24/2026
> Workqueue: ib_addr process_one_req
> RIP: 0010:res_to_rt+0x1c4/0x230 drivers/infiniband/core/restrack.c:138
> RSP: 0018:ffffc9000201f850 EFLAGS: 00010293
> RAX: ffffffff88d00ce5 RBX: ffff88807f0fd4f8 RCX: ffff88801e6e0000
> RDX: 0000000000000000 RSI: ffffffff8fd996f0 RDI: 0000000000000003
> RBP: 0000000000000000 R08: ffff88801e6e0000 R09: 000000000000000a
> R10: 0000000000000009 R11: 0000000000000000 R12: dffffc0000000000
> R13: 1ffff1100fe1fa9f R14: 0000000000000000 R15: 0000000000000003
> FS: 0000000000000000(0000) GS:ffff888125012000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00001d559c3d2000 CR3: 0000000077c4c000 CR4: 00000000003526f0
> Call Trace:
> <TASK>
> rdma_restrack_add+0x5a/0x8a0 drivers/infiniband/core/restrack.c:236
> addr_handler+0x41a/0x5a0 drivers/infiniband/core/cma.c:3534
> process_one_req+0x2eb/0x540 drivers/infiniband/core/addr.c:624
> process_one_work kernel/workqueue.c:3375 [inline]
> process_scheduled_works+0xc4e/0x1630 kernel/workqueue.c:3458
> worker_thread+0xa47/0xfb0 kernel/workqueue.c:3539
> kthread+0x388/0x470 kernel/kthread.c:436
> ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
> </TASK>
> "
>
> In addr_handler(), cma_acquire_dev_by_src_ip() is called to populate
> id_priv->cma_dev and bind the associated ib_device to id_priv->id.device.
> If cma_acquire_dev_by_src_ip() returns an error (non-zero status), the ID
> remains unassociated with any RDMA device.
>
> Previously, rdma_restrack_add(&id_priv->res) was invoked unconditionally
> even when cma_acquire_dev_by_src_ip() failed, passing a resource with a
> NULL dev pointer and triggering the WARN_ON assertion in res_to_rt().
>
> Fix this by only adding the resource to restrack when acquiring the device
> succeeds.
>
> Reported-by: syzbot+72eddfbadda3e3928e72@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=72eddfbadda3e3928e72
> Tested-by: syzbot+72eddfbadda3e3928e72@syzkaller.appspotmail.com
> Fixes: cb5cd0ea4eb3 ("RDMA/core: Add CM to restrack after successful attachment to a device")
>
> Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> ---
> V1 -> V2: Follow Jason's advice to use if/else to handle this problem.
Thanks, Jason.
I have sent this commit to syzbot. From the reply, this commit can also
fix the problem in the commit log.
Zhu Yanjun
> ---
> drivers/infiniband/core/cma.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
> index cc24fddf9aaa..73170b15fc3d 100644
> --- a/drivers/infiniband/core/cma.c
> +++ b/drivers/infiniband/core/cma.c
> @@ -3528,10 +3528,12 @@ static void addr_handler(int status, struct sockaddr *src_addr,
> memcpy(addr, src_addr, rdma_addr_size(src_addr));
> if (!status && !id_priv->cma_dev) {
> status = cma_acquire_dev_by_src_ip(id_priv);
> - if (status)
> + if (status) {
> pr_debug_ratelimited("RDMA CM: ADDR_ERROR: failed to acquire device. status %d\n",
> status);
> - rdma_restrack_add(&id_priv->res);
> + } else {
> + rdma_restrack_add(&id_priv->res);
> + }
> } else if (status) {
> pr_debug_ratelimited("RDMA CM: ADDR_ERROR: failed to resolve IP. status %d\n", status);
> }
^ permalink raw reply [flat|nested] 2+ messages in thread
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2026-08-10 22:01 [PATCH v2 1/1] RDMA/cma: Fix WARNING in res_to_rt Zhu Yanjun
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