| From 7dc189d97bc61f1940e13e2fd4fb2c530ca621c0 Mon Sep 17 00:00:00 2001 |
| From: Avihai Horon <avihaih@mellanox.com> |
| Date: Sun, 26 Jan 2020 19:15:00 +0200 |
| Subject: [PATCH] RDMA/core: Fix invalid memory access in spec_filter_size |
| |
| commit a72f4ac1d778f7bde93dfee69bfc23377ec3d74f upstream. |
| |
| Add a check that the size specified in the flow spec header doesn't cause |
| an overflow when calculating the filter size, and thus prevent access to |
| invalid memory. The following crash from syzkaller revealed it. |
| |
| kasan: CONFIG_KASAN_INLINE enabled |
| kasan: GPF could be caused by NULL-ptr deref or user memory access |
| general protection fault: 0000 [#1] SMP KASAN PTI |
| CPU: 1 PID: 17834 Comm: syz-executor.3 Not tainted 5.5.0-rc5 #2 |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS |
| rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 |
| RIP: 0010:memchr_inv+0xd3/0x330 |
| Code: 89 f9 89 f5 83 e1 07 0f 85 f9 00 00 00 49 89 d5 49 c1 ed 03 45 85 |
| ed 74 6f 48 89 d9 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 <80> 3c 01 |
| 00 0f 85 0d 02 00 00 44 0f b6 e5 48 b8 01 01 01 01 01 01 |
| RSP: 0018:ffffc9000a13fa50 EFLAGS: 00010202 |
| RAX: dffffc0000000000 RBX: 7fff88810de9d820 RCX: 0ffff11021bd3b04 |
| RDX: 000000000000fff8 RSI: 0000000000000000 RDI: 7fff88810de9d820 |
| RBP: 0000000000000000 R08: ffff888110d69018 R09: 0000000000000009 |
| R10: 0000000000000001 R11: ffffed10236267cc R12: 0000000000000004 |
| R13: 0000000000001fff R14: ffff88810de9d820 R15: 0000000000000040 |
| FS: 00007f9ee0e51700(0000) GS:ffff88811b100000(0000) |
| knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 0000000000000000 CR3: 0000000115ea0006 CR4: 0000000000360ee0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 |
| Call Trace: |
| spec_filter_size.part.16+0x34/0x50 |
| ib_uverbs_kern_spec_to_ib_spec_filter+0x691/0x770 |
| ib_uverbs_ex_create_flow+0x9ea/0x1b40 |
| ib_uverbs_write+0xaa5/0xdf0 |
| __vfs_write+0x7c/0x100 |
| vfs_write+0x168/0x4a0 |
| ksys_write+0xc8/0x200 |
| do_syscall_64+0x9c/0x390 |
| entry_SYSCALL_64_after_hwframe+0x44/0xa9 |
| RIP: 0033:0x465b49 |
| Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 |
| f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 |
| f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 |
| RSP: 002b:00007f9ee0e50c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 |
| RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000465b49 |
| RDX: 00000000000003a0 RSI: 00000000200007c0 RDI: 0000000000000004 |
| RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 |
| R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ee0e516bc |
| R13: 00000000004ca2da R14: 000000000070deb8 R15: 00000000ffffffff |
| Modules linked in: |
| Dumping ftrace buffer: |
| (ftrace buffer empty) |
| |
| Fixes: 94e03f11ad1f ("IB/uverbs: Add support for flow tag") |
| Link: https://lore.kernel.org/r/20200126171500.4623-1-leon@kernel.org |
| Signed-off-by: Avihai Horon <avihaih@mellanox.com> |
| Reviewed-by: Maor Gottlieb <maorg@mellanox.com> |
| Signed-off-by: Leon Romanovsky <leonro@mellanox.com> |
| Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c |
| index df8e8ac2c16b..dc6637128114 100644 |
| --- a/drivers/infiniband/core/uverbs_cmd.c |
| +++ b/drivers/infiniband/core/uverbs_cmd.c |
| @@ -2716,12 +2716,6 @@ static int kern_spec_to_ib_spec_action(struct uverbs_attr_bundle *attrs, |
| return 0; |
| } |
| |
| -static size_t kern_spec_filter_sz(const struct ib_uverbs_flow_spec_hdr *spec) |
| -{ |
| - /* Returns user space filter size, includes padding */ |
| - return (spec->size - sizeof(struct ib_uverbs_flow_spec_hdr)) / 2; |
| -} |
| - |
| static ssize_t spec_filter_size(const void *kern_spec_filter, u16 kern_filter_size, |
| u16 ib_real_filter_sz) |
| { |
| @@ -2865,11 +2859,16 @@ int ib_uverbs_kern_spec_to_ib_spec_filter(enum ib_flow_spec_type type, |
| static int kern_spec_to_ib_spec_filter(struct ib_uverbs_flow_spec *kern_spec, |
| union ib_flow_spec *ib_spec) |
| { |
| - ssize_t kern_filter_sz; |
| + size_t kern_filter_sz; |
| void *kern_spec_mask; |
| void *kern_spec_val; |
| |
| - kern_filter_sz = kern_spec_filter_sz(&kern_spec->hdr); |
| + if (check_sub_overflow((size_t)kern_spec->hdr.size, |
| + sizeof(struct ib_uverbs_flow_spec_hdr), |
| + &kern_filter_sz)) |
| + return -EINVAL; |
| + |
| + kern_filter_sz /= 2; |
| |
| kern_spec_val = (void *)kern_spec + |
| sizeof(struct ib_uverbs_flow_spec_hdr); |
| -- |
| 2.7.4 |
| |