[PATCH 4.14 029/237] RDMA/core: Fix protection fault in get_pkey_idx_qp_list

Greg Kroah-Hartman
2020-02-27T14:39:05Z

From: Leon Romanovsky <leonro@mellanox.com>

commit 1dd017882e01d2fcd9c5dbbf1eb376211111c393 upstream.

We don't need to set pkey as valid in case that user set only one of pkey
index or port number, otherwise it will be resulted in NULL pointer
dereference while accessing to uninitialized pkey list. 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: 14753 Comm: syz-executor.2 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:get_pkey_idx_qp_list+0x161/0x2d0
Code: 01 00 00 49 8b 5e 20 4c 39 e3 0f 84 b9 00 00 00 e8 e4 42 6e fe 48
8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04
02 84 c0 74 08 3c 01 0f 8e d0 00 00 00 48 8d 7d 04 48 b8
RSP: 0018:ffffc9000bc6f950 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff82c8bdec
RDX: 0000000000000002 RSI: ffffc900030a8000 RDI: 0000000000000010
RBP: ffff888112c8ce80 R08: 0000000000000004 R09: fffff5200178df1f
R10: 0000000000000001 R11: fffff5200178df1f R12: ffff888115dc4430
R13: ffff888115da8498 R14: ffff888115dc4410 R15: ffff888115da8000
FS: 00007f20777de700(0000) GS:ffff88811b100000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f721000 CR3: 00000001173ca002 CR4: 0000000000360ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
port_pkey_list_insert+0xd7/0x7c0
ib_security_modify_qp+0x6fa/0xfc0
_ib_modify_qp+0x8c4/0xbf0
modify_qp+0x10da/0x16d0
ib_uverbs_modify_qp+0x9a/0x100
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

Fixes: d291f1a65232 ("IB/core: Enforce PKey security on QPs")
Link: https://lore.kernel.org/r/20200212080651.GB679970@unreal
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Message-Id: <20200212080651.GB679970@unreal>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/core/security.c | 24 +++++++++---------------
1 file changed, 9 insertions(+), 15 deletions(-)

--- a/drivers/infiniband/core/security.c
+++ b/drivers/infiniband/core/security.c
@@ -338,22 +338,16 @@ static struct ib_ports_pkeys *get_new_pp
if (!new_pps)
return NULL;

- if (qp_attr_mask & (IB_QP_PKEY_INDEX | IB_QP_PORT)) {
- if (!qp_pps) {
- new_pps->main.port_num = qp_attr->port_num;
- new_pps->main.pkey_index = qp_attr->pkey_index;
- } else {
- new_pps->main.port_num = (qp_attr_mask & IB_QP_PORT) ?
- qp_attr->port_num :
- qp_pps->main.port_num;
-
- new_pps->main.pkey_index =
- (qp_attr_mask & IB_QP_PKEY_INDEX) ?
- qp_attr->pkey_index :
- qp_pps->main.pkey_index;
- }
+ if (qp_attr_mask & IB_QP_PORT)
+ new_pps->main.port_num =
+ (qp_pps) ? qp_pps->main.port_num : qp_attr->port_num;
+ if (qp_attr_mask & IB_QP_PKEY_INDEX)
+ new_pps->main.pkey_index = (qp_pps) ? qp_pps->main.pkey_index :
+ qp_attr->pkey_index;
+ if ((qp_attr_mask & IB_QP_PKEY_INDEX) && (qp_attr_mask & IB_QP_PORT))
new_pps->main.state = IB_PORT_PKEY_VALID;
- } else if (qp_pps) {
+
+ if (!(qp_attr_mask & (IB_QP_PKEY_INDEX || IB_QP_PORT)) && qp_pps) {
new_pps->main.port_num = qp_pps->main.port_num;
new_pps->main.pkey_index = qp_pps->main.pkey_index;
if (qp_pps->main.state != IB_PORT_PKEY_NOT_VALID)