The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 64733956ebba7cc629856f4a6ee35a52bc9c023f Mon Sep 17 00:00:00 2001

From: Mark Zhang markzhang@nvidia.com Date: Sun, 24 Oct 2021 09:08:20 +0300 Subject: [PATCH] RDMA/sa_query: Use strscpy_pad instead of memcpy to copy a string

When copying the device name, the length of the data memcpy copied exceeds the length of the source buffer, which cause the KASAN issue below. Use strscpy_pad() instead.

BUG: KASAN: slab-out-of-bounds in ib_nl_set_path_rec_attrs+0x136/0x320 [ib_core] Read of size 64 at addr ffff88811a10f5e0 by task rping/140263 CPU: 3 PID: 140263 Comm: rping Not tainted 5.15.0-rc1+ #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x7d print_address_description.constprop.0+0x1d/0xa0 kasan_report+0xcb/0x110 kasan_check_range+0x13d/0x180 memcpy+0x20/0x60 ib_nl_set_path_rec_attrs+0x136/0x320 [ib_core] ib_nl_make_request+0x1c6/0x380 [ib_core] send_mad+0x20a/0x220 [ib_core] ib_sa_path_rec_get+0x3e3/0x800 [ib_core] cma_query_ib_route+0x29b/0x390 [rdma_cm] rdma_resolve_route+0x308/0x3e0 [rdma_cm] ucma_resolve_route+0xe1/0x150 [rdma_ucm] ucma_write+0x17b/0x1f0 [rdma_ucm] vfs_write+0x142/0x4d0 ksys_write+0x133/0x160 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f26499aa90f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 5c fd ff ff 48 RSP: 002b:00007f26495f2dc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000000007d0 RCX: 00007f26499aa90f RDX: 0000000000000010 RSI: 00007f26495f2e00 RDI: 0000000000000003 RBP: 00005632a8315440 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f26495f2e00 R13: 00005632a83154e0 R14: 00005632a8315440 R15: 00005632a830a810

Allocated by task 131419: kasan_save_stack+0x1b/0x40 __kasan_kmalloc+0x7c/0x90 proc_self_get_link+0x8b/0x100 pick_link+0x4f1/0x5c0 step_into+0x2eb/0x3d0 walk_component+0xc8/0x2c0 link_path_walk+0x3b8/0x580 path_openat+0x101/0x230 do_filp_open+0x12e/0x240 do_sys_openat2+0x115/0x280 __x64_sys_openat+0xce/0x140 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixes: 2ca546b92a02 ("IB/sa: Route SA pathrecord query through netlink") Link: https://lore.kernel.org/r/72ede0f6dab61f7f23df9ac7a70666e07ef314b0.163505549... Signed-off-by: Mark Zhang markzhang@nvidia.com Reviewed-by: Mark Bloch mbloch@nvidia.com Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com

diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index a20b8108e160..c00f8e28aab7 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -706,8 +706,9 @@ static void ib_nl_set_path_rec_attrs(struct sk_buff *skb,

/* Construct the family header first */ header = skb_put(skb, NLMSG_ALIGN(sizeof(*header))); - memcpy(header->device_name, dev_name(&query->port->agent->device->dev), - LS_DEVICE_NAME_MAX); + strscpy_pad(header->device_name, + dev_name(&query->port->agent->device->dev), + LS_DEVICE_NAME_MAX); header->port_num = query->port->port_num;

if ((comp_mask & IB_SA_PATH_REC_REVERSIBLE) &&