This is a note to let you know that I've just added the patch titled

RDMA/ucma: Fix access to non-initialized CM_ID object

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: rdma-ucma-fix-access-to-non-initialized-cm_id-object.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 7688f2c3bbf55e52388e37ac5d63ca471a7712e1 Mon Sep 17 00:00:00 2001

From: Leon Romanovsky leonro@mellanox.com Date: Tue, 13 Mar 2018 11:43:23 +0200 Subject: RDMA/ucma: Fix access to non-initialized CM_ID object

From: Leon Romanovsky leonro@mellanox.com

commit 7688f2c3bbf55e52388e37ac5d63ca471a7712e1 upstream.

The attempt to join multicast group without ensuring that CMA device exists will lead to the following crash reported by syzkaller.

[ 64.076794] BUG: KASAN: null-ptr-deref in rdma_join_multicast+0x26e/0x12c0 [ 64.076797] Read of size 8 at addr 00000000000000b0 by task join/691 [ 64.076797] [ 64.076800] CPU: 1 PID: 691 Comm: join Not tainted 4.16.0-rc1-00219-gb97853b65b93 #23 [ 64.076802] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-proj4 [ 64.076803] Call Trace: [ 64.076809] dump_stack+0x5c/0x77 [ 64.076817] kasan_report+0x163/0x380 [ 64.085859] ? rdma_join_multicast+0x26e/0x12c0 [ 64.086634] rdma_join_multicast+0x26e/0x12c0 [ 64.087370] ? rdma_disconnect+0xf0/0xf0 [ 64.088579] ? __radix_tree_replace+0xc3/0x110 [ 64.089132] ? node_tag_clear+0x81/0xb0 [ 64.089606] ? idr_alloc_u32+0x12e/0x1a0 [ 64.090517] ? __fprop_inc_percpu_max+0x150/0x150 [ 64.091768] ? tracing_record_taskinfo+0x10/0xc0 [ 64.092340] ? idr_alloc+0x76/0xc0 [ 64.092951] ? idr_alloc_u32+0x1a0/0x1a0 [ 64.093632] ? ucma_process_join+0x23d/0x460 [ 64.094510] ucma_process_join+0x23d/0x460 [ 64.095199] ? ucma_migrate_id+0x440/0x440 [ 64.095696] ? futex_wake+0x10b/0x2a0 [ 64.096159] ucma_join_multicast+0x88/0xe0 [ 64.096660] ? ucma_process_join+0x460/0x460 [ 64.097540] ? _copy_from_user+0x5e/0x90 [ 64.098017] ucma_write+0x174/0x1f0 [ 64.098640] ? ucma_resolve_route+0xf0/0xf0 [ 64.099343] ? rb_erase_cached+0x6c7/0x7f0 [ 64.099839] __vfs_write+0xc4/0x350 [ 64.100622] ? perf_syscall_enter+0xe4/0x5f0 [ 64.101335] ? kernel_read+0xa0/0xa0 [ 64.103525] ? perf_sched_cb_inc+0xc0/0xc0 [ 64.105510] ? syscall_exit_register+0x2a0/0x2a0 [ 64.107359] ? __switch_to+0x351/0x640 [ 64.109285] ? fsnotify+0x899/0x8f0 [ 64.111610] ? fsnotify_unmount_inodes+0x170/0x170 [ 64.113876] ? __fsnotify_update_child_dentry_flags+0x30/0x30 [ 64.115813] ? ring_buffer_record_is_on+0xd/0x20 [ 64.117824] ? __fget+0xa8/0xf0 [ 64.119869] vfs_write+0xf7/0x280 [ 64.122001] SyS_write+0xa1/0x120 [ 64.124213] ? SyS_read+0x120/0x120 [ 64.126644] ? SyS_read+0x120/0x120 [ 64.128563] do_syscall_64+0xeb/0x250 [ 64.130732] entry_SYSCALL_64_after_hwframe+0x21/0x86 [ 64.132984] RIP: 0033:0x7f5c994ade99 [ 64.135699] RSP: 002b:00007f5c99b97d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 64.138740] RAX: ffffffffffffffda RBX: 00000000200001e4 RCX: 00007f5c994ade99 [ 64.141056] RDX: 00000000000000a0 RSI: 00000000200001c0 RDI: 0000000000000015 [ 64.143536] RBP: 00007f5c99b97ec0 R08: 0000000000000000 R09: 0000000000000000 [ 64.146017] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c99b97fc0 [ 64.148608] R13: 0000000000000000 R14: 00007fff660e1c40 R15: 00007f5c99b989c0 [ 64.151060] [ 64.153703] Disabling lock debugging due to kernel taint [ 64.156032] BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0 [ 64.159066] IP: rdma_join_multicast+0x26e/0x12c0 [ 64.161451] PGD 80000001d0298067 P4D 80000001d0298067 PUD 1dea39067 PMD 0 [ 64.164442] Oops: 0000 [#1] SMP KASAN PTI [ 64.166817] CPU: 1 PID: 691 Comm: join Tainted: G B 4.16.0-rc1-00219-gb97853b65b93 #23 [ 64.170004] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-proj4 [ 64.174985] RIP: 0010:rdma_join_multicast+0x26e/0x12c0 [ 64.177246] RSP: 0018:ffff8801c8207860 EFLAGS: 00010282 [ 64.179901] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff94789522 [ 64.183344] RDX: 1ffffffff2d50fa5 RSI: 0000000000000297 RDI: 0000000000000297 [ 64.186237] RBP: ffff8801c8207a50 R08: 0000000000000000 R09: ffffed0039040ea7 [ 64.189328] R10: 0000000000000001 R11: ffffed0039040ea6 R12: 0000000000000000 [ 64.192634] R13: 0000000000000000 R14: ffff8801e2022800 R15: ffff8801d4ac2400 [ 64.196105] FS: 00007f5c99b98700(0000) GS:ffff8801e5d00000(0000) knlGS:0000000000000000 [ 64.199211] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 64.202046] CR2: 00000000000000b0 CR3: 00000001d1c48004 CR4: 00000000003606a0 [ 64.205032] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 64.208221] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 64.211554] Call Trace: [ 64.213464] ? rdma_disconnect+0xf0/0xf0 [ 64.216124] ? __radix_tree_replace+0xc3/0x110 [ 64.219337] ? node_tag_clear+0x81/0xb0 [ 64.222140] ? idr_alloc_u32+0x12e/0x1a0 [ 64.224422] ? __fprop_inc_percpu_max+0x150/0x150 [ 64.226588] ? tracing_record_taskinfo+0x10/0xc0 [ 64.229763] ? idr_alloc+0x76/0xc0 [ 64.232186] ? idr_alloc_u32+0x1a0/0x1a0 [ 64.234505] ? ucma_process_join+0x23d/0x460 [ 64.237024] ucma_process_join+0x23d/0x460 [ 64.240076] ? ucma_migrate_id+0x440/0x440 [ 64.243284] ? futex_wake+0x10b/0x2a0 [ 64.245302] ucma_join_multicast+0x88/0xe0 [ 64.247783] ? ucma_process_join+0x460/0x460 [ 64.250841] ? _copy_from_user+0x5e/0x90 [ 64.253878] ucma_write+0x174/0x1f0 [ 64.257008] ? ucma_resolve_route+0xf0/0xf0 [ 64.259877] ? rb_erase_cached+0x6c7/0x7f0 [ 64.262746] __vfs_write+0xc4/0x350 [ 64.265537] ? perf_syscall_enter+0xe4/0x5f0 [ 64.267792] ? kernel_read+0xa0/0xa0 [ 64.270358] ? perf_sched_cb_inc+0xc0/0xc0 [ 64.272575] ? syscall_exit_register+0x2a0/0x2a0 [ 64.275367] ? __switch_to+0x351/0x640 [ 64.277700] ? fsnotify+0x899/0x8f0 [ 64.280530] ? fsnotify_unmount_inodes+0x170/0x170 [ 64.283156] ? __fsnotify_update_child_dentry_flags+0x30/0x30 [ 64.286182] ? ring_buffer_record_is_on+0xd/0x20 [ 64.288749] ? __fget+0xa8/0xf0 [ 64.291136] vfs_write+0xf7/0x280 [ 64.292972] SyS_write+0xa1/0x120 [ 64.294965] ? SyS_read+0x120/0x120 [ 64.297474] ? SyS_read+0x120/0x120 [ 64.299751] do_syscall_64+0xeb/0x250 [ 64.301826] entry_SYSCALL_64_after_hwframe+0x21/0x86 [ 64.304352] RIP: 0033:0x7f5c994ade99 [ 64.306711] RSP: 002b:00007f5c99b97d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 64.309577] RAX: ffffffffffffffda RBX: 00000000200001e4 RCX: 00007f5c994ade99 [ 64.312334] RDX: 00000000000000a0 RSI: 00000000200001c0 RDI: 0000000000000015 [ 64.315783] RBP: 00007f5c99b97ec0 R08: 0000000000000000 R09: 0000000000000000 [ 64.318365] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5c99b97fc0 [ 64.320980] R13: 0000000000000000 R14: 00007fff660e1c40 R15: 00007f5c99b989c0 [ 64.323515] Code: e8 e8 79 08 ff 4c 89 ff 45 0f b6 a7 b8 01 00 00 e8 68 7c 08 ff 49 8b 1f 4d 89 e5 49 c1 e4 04 48 8 [ 64.330753] RIP: rdma_join_multicast+0x26e/0x12c0 RSP: ffff8801c8207860 [ 64.332979] CR2: 00000000000000b0 [ 64.335550] ---[ end trace 0c00c17a408849c1 ]---

Reported-by: syzbot+e6aba77967bd72cbc9d6@syzkaller.appspotmail.com Fixes: c8f6a362bf3e ("RDMA/cma: Add multicast communication support") Signed-off-by: Leon Romanovsky leonro@mellanox.com Reviewed-by: Sean Hefty sean.hefty@intel.com Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/infiniband/core/cma.c | 3 +++ 1 file changed, 3 insertions(+)

--- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -3743,6 +3743,9 @@ int rdma_join_multicast(struct rdma_cm_i struct cma_multicast *mc; int ret;

+ if (!id->device) + return -EINVAL; + id_priv = container_of(id, struct rdma_id_private, id); if (!cma_comp(id_priv, RDMA_CM_ADDR_BOUND) && !cma_comp(id_priv, RDMA_CM_ADDR_RESOLVED))

Patches currently in stable-queue which might be from leonro@mellanox.com are

queue-4.4/rdma-ucma-fix-access-to-non-initialized-cm_id-object.patch