Syzbot reported a slab-use-after-free with the following call trace: ================================================================== BUG: KASAN: slab-use-after-free in nla_put+0xd3/0x150 lib/nlattr.c:1099 Read of size 5 at addr ffff888140ea1c60 by task syz.0.988/10025 CPU: 0 UID: 0 PID: 10025 Comm: syz.0.988 Not tainted 6.14.0-rc4-syzkaller-00859-gf77f12010f67 #0 Hardware name: Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x16e/0x5b0 mm/kasan/report.c:521 kasan_report+0x143/0x180 mm/kasan/report.c:634 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 nla_put+0xd3/0x150 lib/nlattr.c:1099 nla_put_string include/net/netlink.h:1621 [inline] fill_nldev_handle+0x16e/0x200 drivers/infiniband/core/nldev.c:265 rdma_nl_notify_event+0x561/0xef0 drivers/infiniband/core/nldev.c:2857 ib_device_notify_register+0x22/0x230 drivers/infiniband/core/device.c:1344 ib_register_device+0x1292/0x1460 drivers/infiniband/core/device.c:1460 rxe_register_device+0x233/0x350 drivers/infiniband/sw/rxe/rxe_verbs.c:1540 rxe_net_add+0x74/0xf0 drivers/infiniband/sw/rxe/rxe_net.c:550 rxe_newlink+0xde/0x1a0 drivers/infiniband/sw/rxe/rxe.c:212 nldev_newlink+0x5ea/0x680 drivers/infiniband/core/nldev.c:1795 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x6dd/0x9e0 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:709 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:724 ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 ___sys_sendmsg net/socket.c:2618 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2650 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f42d1b8d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 ... RSP: 002b:00007f42d2960038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f42d1da6320 RCX: 00007f42d1b8d169 RDX: 0000000000000000 RSI: 00004000000002c0 RDI: 000000000000000c RBP: 00007f42d1c0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f42d1da6320 R15: 00007ffe399344a8 </TASK> Allocated by task 10025: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_node_track_caller_noprof+0x28b/0x4c0 mm/slub.c:4313 __kmemdup_nul mm/util.c:61 [inline] kstrdup+0x42/0x100 mm/util.c:81 kobject_set_name_vargs+0x61/0x120 lib/kobject.c:274 dev_set_name+0xd5/0x120 drivers/base/core.c:3468 assign_name drivers/infiniband/core/device.c:1202 [inline] ib_register_device+0x178/0x1460 drivers/infiniband/core/device.c:1384 rxe_register_device+0x233/0x350 drivers/infiniband/sw/rxe/rxe_verbs.c:1540 rxe_net_add+0x74/0xf0 drivers/infiniband/sw/rxe/rxe_net.c:550 rxe_newlink+0xde/0x1a0 drivers/infiniband/sw/rxe/rxe.c:212 nldev_newlink+0x5ea/0x680 drivers/infiniband/core/nldev.c:1795 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x6dd/0x9e0 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:709 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:724 ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 ___sys_sendmsg net/socket.c:2618 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2650 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 10035: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x196/0x430 mm/slub.c:4757 kobject_rename+0x38f/0x410 lib/kobject.c:524 device_rename+0x16a/0x200 drivers/base/core.c:4525 ib_device_rename+0x270/0x710 drivers/infiniband/core/device.c:402 nldev_set_doit+0x30e/0x4c0 drivers/infiniband/core/nldev.c:1146 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x6dd/0x9e0 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:709 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:724 ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 ___sys_sendmsg net/socket.c:2618 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2650 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f This is because if rename device happens, the old name is freed in ib_device_rename() with lock, but fill_nldev_handle() may visit the dev name locklessly triggered by rxe_newlink(). Fix this by add lock around rdma_nl_notify_event() in ib_device_notify_register(). Reported-by: syzbot+f60349ba1f9f08df349f@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=25bc6f0ed2b88b9eb9b8 Fixes: 9cbed5aab5ae ("RDMA/nldev: Add support for RDMA monitoring") Signed-off-by: Wang Liang <wangliang74@xxxxxxxxxx> --- drivers/infiniband/core/device.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index 0ded91f056f3..4536621ada0d 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -1341,7 +1341,9 @@ static void ib_device_notify_register(struct ib_device *device) u32 port; int ret; + down_write(&devices_rwsem); ret = rdma_nl_notify_event(device, 0, RDMA_REGISTER_EVENT); + up_write(&devices_rwsem); if (ret) return; -- 2.34.1
