KASAN: null-ptr-deref Read in trace_event_raw_event_rtrs_clt_conn_class

Status: moderation: reported on 2026/08/22 00:21
Subsystems: rdma
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+54a179d6b42f78516a13@syzkaller.appspotmail.com
First crash: 5d06h, last: 1h34m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
a29a34ab assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ KASAN: null-ptr-deref Read in trace_event_raw_event_rtrs_clt_conn_class 2026/08/19 03:37 2026/08/19 03:37 2026/08/19 03:40 1e72964b

Sample crash report:
rtrs_client L2098: <s1>: Failed to resolve address, err: -ENODEV
rtrs_client L2641: <s1>: init_conns() failed: err=-ENODEV path=<invalid address family>@ip:127.0.0.1 [:0]
==================================================================
BUG: KASAN: null-ptr-deref in do_trace_event_raw_event_rtrs_clt_conn_class drivers/infiniband/ulp/rtrs/rtrs-clt-trace.h:58 [inline]
BUG: KASAN: null-ptr-deref in trace_event_raw_event_rtrs_clt_conn_class+0x220/0x480 drivers/infiniband/ulp/rtrs/rtrs-clt-trace.h:36
Read of size 255 at addr 0000000000000000 by task syz.5.304/6302

CPU: 1 UID: 0 PID: 6302 Comm: syz.5.304 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_report+0x58/0x84 mm/kasan/report.c:485
 kasan_report+0x8c/0xc4 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x17c/0x1ac mm/kasan/generic.c:200
 __asan_memcpy+0x3c/0x84 mm/kasan/shadow.c:105
 do_trace_event_raw_event_rtrs_clt_conn_class drivers/infiniband/ulp/rtrs/rtrs-clt-trace.h:58 [inline]
 trace_event_raw_event_rtrs_clt_conn_class+0x220/0x480 drivers/infiniband/ulp/rtrs/rtrs-clt-trace.h:36
 __traceiter_rtrs_clt_close_conns+0x74/0xc8 drivers/infiniband/ulp/rtrs/rtrs-clt-trace.h:77
 __do_trace_rtrs_clt_close_conns drivers/infiniband/ulp/rtrs/rtrs-clt-trace.h:77 [inline]
 trace_rtrs_clt_close_conns drivers/infiniband/ulp/rtrs/rtrs-clt-trace.h:77 [inline]
 rtrs_clt_close_conns+0x2f0/0x40c drivers/infiniband/ulp/rtrs/rtrs-clt.c:1949
 rtrs_clt_open+0xa6c/0xd54 drivers/infiniband/ulp/rtrs/rtrs-clt.c:2858
 find_and_get_or_create_sess drivers/block/rnbd/rnbd-clt.c:1268 [inline]
 rnbd_clt_map_device+0xcb8/0x1f64 drivers/block/rnbd/rnbd-clt.c:1551
 rnbd_clt_map_device_store+0x900/0xad8 drivers/block/rnbd/rnbd-clt-sysfs.c:612
 dev_attr_store+0x6c/0x90 drivers/base/core.c:2505
 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x84/0x98 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x19c/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:758
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/22 20:54 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: null-ptr-deref Read in trace_event_raw_event_rtrs_clt_conn_class
2026/08/21 22:54 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: null-ptr-deref Read in trace_event_raw_event_rtrs_clt_conn_class
2026/08/17 15:57 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 21d6ac051080 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: null-ptr-deref Read in trace_event_raw_event_rtrs_clt_conn_class
* Struck through repros no longer work on HEAD.