It's possible mr_pd(mr) returns NULL if rxe_mr_alloc() fails.
it fixes below panic:
[ 114.163945] RPC: Registered rdma backchannel transport module.
[ 116.868003] eth0 speed is unknown, defaulting to 1000
[ 120.173114] rdma_rxe: rxe_mr_init_user: Unable to allocate memory for map
[ 120.173159] ==================================================================
[ 120.173161] BUG: KASAN: null-ptr-deref in __rxe_put+0x18/0x60 [rdma_rxe]
[ 120.173194] Write of size 4 at addr 0000000000000080 by task rdma_flush_serv/685
[ 120.173197]
[ 120.173199] CPU: 0 PID: 685 Comm: rdma_flush_serv Not tainted 5.19.0-rc1-roce-flush+ #90
[ 120.173203] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014
[ 120.173208] Call Trace:
[ 120.173216] <TASK>
[ 120.173217] dump_stack_lvl+0x34/0x44
[ 120.173250] kasan_report+0xab/0x120
[ 120.173261] ? __rxe_put+0x18/0x60 [rdma_rxe]
[ 120.173277] kasan_check_range+0xf9/0x1e0
[ 120.173282] __rxe_put+0x18/0x60 [rdma_rxe]
[ 120.173311] rxe_mr_cleanup+0x21/0x140 [rdma_rxe]
[ 120.173328] __rxe_cleanup+0xff/0x1d0 [rdma_rxe]
[ 120.173344] rxe_reg_user_mr+0xa7/0xc0 [rdma_rxe]
[ 120.173360] ib_uverbs_reg_mr+0x265/0x460 [ib_uverbs]
[ 120.173387] ? ib_uverbs_modify_qp+0x8b/0xd0 [ib_uverbs]
[ 120.173433] ? ib_uverbs_create_cq+0x100/0x100 [ib_uverbs]
[ 120.173461] ? uverbs_fill_udata+0x1d8/0x330 [ib_uverbs]
[ 120.173488] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x19d/0x250 [ib_uverbs]
[ 120.173517] ? ib_uverbs_handler_UVERBS_METHOD_QUERY_CONTEXT+0x190/0x190 [ib_uverbs]
[ 120.173547] ? radix_tree_next_chunk+0x31e/0x410
[ 120.173559] ? uverbs_fill_udata+0x255/0x330 [ib_uverbs]
[ 120.173587] ib_uverbs_cmd_verbs+0x11c2/0x1450 [ib_uverbs]
[ 120.173616] ? ucma_put_ctx+0x16/0x50 [rdma_ucm]
[ 120.173623] ? __rcu_read_unlock+0x43/0x60
[ 120.173633] ? ib_uverbs_handler_UVERBS_METHOD_QUERY_CONTEXT+0x190/0x190 [ib_uverbs]
[ 120.173661] ? uverbs_fill_udata+0x330/0x330 [ib_uverbs]
[ 120.173711] ? avc_ss_reset+0xb0/0xb0
[ 120.173722] ? vfs_fileattr_set+0x450/0x450
[ 120.173742] ? should_fail+0x78/0x2b0
[ 120.173745] ? __fsnotify_parent+0x38a/0x4e0
[ 120.173764] ? ioctl_has_perm.constprop.0.isra.0+0x198/0x210
[ 120.173784] ? should_fail+0x78/0x2b0
[ 120.173787] ? selinux_bprm_creds_for_exec+0x550/0x550
[ 120.173792] ib_uverbs_ioctl+0x114/0x1b0 [ib_uverbs]
[ 120.173820] ? ib_uverbs_cmd_verbs+0x1450/0x1450 [ib_uverbs]
[ 120.173861] __x64_sys_ioctl+0xb4/0xf0
[ 120.173867] do_syscall_64+0x3b/0x90
[ 120.173877] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 120.173884] RIP: 0033:0x7f4b563c14eb
[ 120.173889] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 55 b9 0c 00 f7 d8 64 89 01 48
[ 120.173892] RSP: 002b:00007ffe0e4a6fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_mr.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 9a5c2af6a56f..cec5775a72f2 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -695,8 +695,10 @@ int rxe_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
void rxe_mr_cleanup(struct rxe_pool_elem *elem)
{
struct rxe_mr *mr = container_of(elem, typeof(*mr), elem);
+ struct rxe_pd *pd = mr_pd(mr);
- rxe_put(mr_pd(mr));
+ if (pd)
+ rxe_put(pd);
ib_umem_release(mr->umem);
--
2.31.1
