[PATCH net-next] bnxt_en: fix accessing vnic_info before allocating it
From: Alexander Lobakin
Date: Mon Feb 26 2024 - 10:08:41 EST
bnxt_alloc_mem() dereferences ::vnic_info in the variable declaration
block, but allocates it much later. As a result, the following crash
happens on my setup:
BUG: kernel NULL pointer dereference, address: 0000000000000090
fbcon: Taking over console
#PF: supervisor write access in kernel mode
#PF: error_code (0x0002) - not-present page
PGD 12f382067 P4D 0
Oops: 8002 [#1] PREEMPT SMP NOPTI
CPU: 47 PID: 2516 Comm: NetworkManager Not tainted 6.8.0-rc5-libeth+ #49
Hardware name: Intel Corporation M50CYP2SBSTD/M58CYP2SBSTD, BIOS SE5C620.86B.01.01.0088.2305172341 05/17/2023
RIP: 0010:bnxt_alloc_mem+0x1609/0x1910 [bnxt_en]
Code: 81 c8 48 83 c8 08 31 c9 e9 d7 fe ff ff c7 44 24 Oc 00 00 00 00 49 89 d5 e9 2d fe ff ff 41 89 c6 e9 88 00 00 00 48 8b 44 24 50 <80> 88 90 00 00 00 Od 8b 43 74 a8 02 75 1e f6 83 14 02 00 00 80 74
RSP: 0018:ff3f25580f3432c8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ff15a5cfc45249e0 RCX: 0000002079777000
RDX: ff15a5dfb9767000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ff15a5dfb9777000 R11: ffffff8000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000020 R15: ff15a5cfce34f540
FS: 000007fb9a160500(0000) GS:ff15a5dfbefc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CRO: 0000000080050033
CR2: 0000000000000090 CR3: 0000000109efc00Z CR4: 0000000000771ef0
DR0: 0000000000000000 DR1: 0000000000000000 DRZ: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? __die_body+0x68/0xb0
? page_fault_oops+0x3a6/0x400
? exc_page_fault+0x7a/0x1b0
? asm_exc_page_fault+0x26/8x30
? bnxt_alloc_mem+0x1609/0x1910 [bnxt_en]
? bnxt_alloc_mem+0x1389/8x1918 [bnxt_en]
_bnxt_open_nic+0x198/0xa50 [bnxt_en]
? bnxt_hurm_if_change+0x287/0x3d0 [bnxt_en]
bnxt_open+0xeb/0x1b0 [bnxt_en]
_dev_open+0x12e/0x1f0
_dev_change_flags+0xb0/0x200
dev_change_flags+0x25/0x60
do_setlink+0x463/0x1260
? sock_def_readable+0x14/0xc0
? rtnl_getlink+0x4b9/0x590
? _nla_validate_parse+0x91/0xfa0
rtnl_newlink+0xbac/0xe40
<...>
Don't create a variable and dereference the first array member directly
since it's used only once in the code.
Fixes: ef4ee64e9990 ("bnxt_en: Define BNXT_VNIC_DEFAULT for the default vnic index")
Signed-off-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 9968d67e6c77..a15e6d31fc22 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -5004,7 +5004,6 @@ static void bnxt_free_mem(struct bnxt *bp, bool irq_re_init)
static int bnxt_alloc_mem(struct bnxt *bp, bool irq_re_init)
{
- struct bnxt_vnic_info *vnic0 = &bp->vnic_info[BNXT_VNIC_DEFAULT];
int i, j, rc, size, arr_size;
void *bnapi;
@@ -5133,8 +5132,9 @@ static int bnxt_alloc_mem(struct bnxt *bp, bool irq_re_init)
if (rc)
goto alloc_mem_err;
- vnic0->flags |= BNXT_VNIC_RSS_FLAG | BNXT_VNIC_MCAST_FLAG |
- BNXT_VNIC_UCAST_FLAG;
+ bp->vnic_info[BNXT_VNIC_DEFAULT].flags |= BNXT_VNIC_RSS_FLAG |
+ BNXT_VNIC_MCAST_FLAG |
+ BNXT_VNIC_UCAST_FLAG;
if (BNXT_SUPPORTS_NTUPLE_VNIC(bp) && (bp->flags & BNXT_FLAG_RFS))
bp->vnic_info[BNXT_VNIC_NTUPLE].flags |=
BNXT_VNIC_RSS_FLAG | BNXT_VNIC_NTUPLE_FLAG;
--
2.43.2