From: Selvin Xavier selvin.xavier@broadcom.com
commit 9a4467a6b282a299b932608ac2c9034f8415359f upstream.
The driver returns an error code for MR dereg, but frees the MR structure. When the MR dereg is retried due to previous error, the system crashes as the structure is already freed.
BUG: unable to handle kernel NULL pointer dereference at 00000000000001b8 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 7 PID: 12178 Comm: ib_send_bw Kdump: loaded Not tainted 4.18.0-124.el8.x86_64 #1 Hardware name: Dell Inc. PowerEdge R430/03XKDV, BIOS 1.1.10 03/10/2015 RIP: 0010:__dev_printk+0x2a/0x70 Code: 0f 1f 44 00 00 49 89 d1 48 85 f6 0f 84 f6 2b 00 00 4c 8b 46 70 4d 85 c0 75 04 4c 8b 46 10 48 8b 86 a8 00 00 00 48 85 c0 74 16 <48> 8b 08 0f be 7f 01 48 c7 c2 13 ac ac 83 83 ef 30 e9 10 fe ff ff RSP: 0018:ffffaf7c04607a60 EFLAGS: 00010006 RAX: 00000000000001b8 RBX: ffffa0010c91c488 RCX: 0000000000000246 RDX: ffffaf7c04607a68 RSI: ffffa0010c91caa8 RDI: ffffffff83a788eb RBP: ffffaf7c04607ac8 R08: 0000000000000000 R09: ffffaf7c04607a68 R10: 0000000000000000 R11: 0000000000000001 R12: ffffaf7c04607b90 R13: 000000000000000e R14: 0000000000000000 R15: 00000000ffffa001 FS: 0000146fa1f1cdc0(0000) GS:ffffa0012fac0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001b8 CR3: 000000007680a003 CR4: 00000000001606e0 Call Trace: dev_err+0x6c/0x90 ? dev_printk_emit+0x4e/0x70 bnxt_qplib_rcfw_send_message+0x594/0x660 [bnxt_re] ? dev_err+0x6c/0x90 bnxt_qplib_free_mrw+0x80/0xe0 [bnxt_re] bnxt_re_dereg_mr+0x2e/0xd0 [bnxt_re] ib_dereg_mr+0x2f/0x50 [ib_core] destroy_hw_idr_uobject+0x20/0x70 [ib_uverbs] uverbs_destroy_uobject+0x2e/0x170 [ib_uverbs] __uverbs_cleanup_ufile+0x6e/0x90 [ib_uverbs] uverbs_destroy_ufile_hw+0x61/0x130 [ib_uverbs] ib_uverbs_close+0x1f/0x80 [ib_uverbs] __fput+0xb7/0x230 task_work_run+0x8a/0xb0 do_exit+0x2da/0xb40 ... RIP: 0033:0x146fa113a387 Code: Bad RIP value. RSP: 002b:00007fff945d1478 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02 RAX: 0000000000000000 RBX: 000055a248908d70 RCX: 0000000000000000 RDX: 0000146fa1f2b000 RSI: 0000000000000001 RDI: 000055a248906488 RBP: 000055a248909630 R08: 0000000000010000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000055a248906488 R13: 0000000000000001 R14: 0000000000000000 R15: 000055a2489095f0
Do not free the MR structures, when driver returns error to the stack.
Fixes: 872f3578241d ("RDMA/bnxt_re: Add support for MRs with Huge pages") Link: https://lore.kernel.org/r/1574671174-5064-2-git-send-email-selvin.xavier@bro... Signed-off-by: Selvin Xavier selvin.xavier@broadcom.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/hw/bnxt_re/ib_verbs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c +++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c @@ -3368,8 +3368,10 @@ int bnxt_re_dereg_mr(struct ib_mr *ib_mr int rc;
rc = bnxt_qplib_free_mrw(&rdev->qplib_res, &mr->qplib_mr); - if (rc) + if (rc) { dev_err(rdev_to_dev(rdev), "Dereg MR failed: %#x\n", rc); + return rc; + }
if (mr->pages) { rc = bnxt_qplib_free_fast_reg_page_list(&rdev->qplib_res,