To avoid the following kernel panic when calling kmem_cache_create() with a NULL pointer from pool_cache(), Block the rxe_param_set_add() from running if the rdma_rxe module is not loaded. BUG: unable to handle kernel NULL pointer dereference at 000000000000000b PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 4 PID: 8512 Comm: modprobe Kdump: loaded Not tainted 4.18.0-231.el8.x86_64 #1 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 10/02/2018 RIP: 0010:kmem_cache_alloc+0xd1/0x1b0 Code: 8b 57 18 45 8b 77 1c 48 8b 5c 24 30 0f 1f 44 00 00 5b 48 89 e8 5d 41 5c 41 5d 41 5e 41 5f c3 81 e3 00 00 10 00 75 0e 4d 89 fe <41> f6 47 0b 04 0f 84 6c ff ff ff 4c 89 ff e8 cc da 01 00 49 89 c6 RSP: 0018:ffffa2b8c773f9d0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000005 RDX: 0000000000000004 RSI: 00000000006080c0 RDI: 0000000000000000 RBP: ffff8ea0a8634fd0 R08: ffffa2b8c773f988 R09: 00000000006000c0 R10: 0000000000000000 R11: 0000000000000230 R12: 00000000006080c0 R13: ffffffffc0a97fc8 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f9138ed9740(0000) GS:ffff8ea4ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000000b CR3: 000000046d59a000 CR4: 00000000003406e0 Call Trace: rxe_alloc+0xc8/0x160 [rdma_rxe] rxe_get_dma_mr+0x25/0xb0 [rdma_rxe] __ib_alloc_pd+0xcb/0x160 [ib_core] ib_mad_init_device+0x296/0x8b0 [ib_core] add_client_context+0x11a/0x160 [ib_core] enable_device_and_get+0xdc/0x1d0 [ib_core] ib_register_device+0x572/0x6b0 [ib_core] ? crypto_create_tfm+0x32/0xe0 ? crypto_create_tfm+0x7a/0xe0 ? crypto_alloc_tfm+0x58/0xf0 rxe_register_device+0x19d/0x1c0 [rdma_rxe] rxe_net_add+0x3d/0x70 [rdma_rxe] ? dev_get_by_name_rcu+0x73/0x90 rxe_param_set_add+0xaf/0xc0 [rdma_rxe] parse_args+0x179/0x370 ? ref_module+0x1b0/0x1b0 load_module+0x135e/0x17e0 ? ref_module+0x1b0/0x1b0 ? __do_sys_init_module+0x13b/0x180 __do_sys_init_module+0x13b/0x180 do_syscall_64+0x5b/0x1a0 entry_SYSCALL_64_after_hwframe+0x65/0xca RIP: 0033:0x7f9137ed296e Fixes: 8700e3e7c485 ("Soft RoCE driver") Signed-off-by: Kamal Heib <kamalheib1@xxxxxxxxx> --- drivers/infiniband/sw/rxe/rxe.c | 4 ++++ drivers/infiniband/sw/rxe/rxe.h | 2 ++ drivers/infiniband/sw/rxe/rxe_sysfs.c | 5 +++++ 3 files changed, 11 insertions(+) diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c index 907203afbd99..88b5c866f5ab 100644 --- a/drivers/infiniband/sw/rxe/rxe.c +++ b/drivers/infiniband/sw/rxe/rxe.c @@ -40,6 +40,8 @@ MODULE_AUTHOR("Bob Pearson, Frank Zago, John Groves, Kamal Heib"); MODULE_DESCRIPTION("Soft RDMA transport"); MODULE_LICENSE("Dual BSD/GPL"); +bool rxe_is_loaded; + /* free resources for a rxe device all objects created for this device must * have been destroyed */ @@ -315,6 +317,7 @@ static int __init rxe_module_init(void) return err; rdma_link_register(&rxe_link_ops); + rxe_is_loaded = true; pr_info("loaded\n"); return 0; } @@ -326,6 +329,7 @@ static void __exit rxe_module_exit(void) rxe_net_exit(); rxe_cache_exit(); + rxe_is_loaded = false; pr_info("unloaded\n"); } diff --git a/drivers/infiniband/sw/rxe/rxe.h b/drivers/infiniband/sw/rxe/rxe.h index fb07eed9e402..d9b71b5e2fba 100644 --- a/drivers/infiniband/sw/rxe/rxe.h +++ b/drivers/infiniband/sw/rxe/rxe.h @@ -67,6 +67,8 @@ #define RXE_ROCE_V2_SPORT (0xc000) +extern bool rxe_is_loaded; + static inline u32 rxe_crc32(struct rxe_dev *rxe, u32 crc, void *next, size_t len) { diff --git a/drivers/infiniband/sw/rxe/rxe_sysfs.c b/drivers/infiniband/sw/rxe/rxe_sysfs.c index ccda5f5a3bc0..12c7ca0764d5 100644 --- a/drivers/infiniband/sw/rxe/rxe_sysfs.c +++ b/drivers/infiniband/sw/rxe/rxe_sysfs.c @@ -61,6 +61,11 @@ static int rxe_param_set_add(const char *val, const struct kernel_param *kp) struct net_device *ndev; struct rxe_dev *exists; + if (!rxe_is_loaded) { + pr_err("Please make sure to load the rdma_rxe module first\n"); + return -EINVAL; + } + len = sanitize_arg(val, intf, sizeof(intf)); if (!len) { pr_err("add: invalid interface name\n"); -- 2.26.2