[PATCH AUTOSEL 4.14 01/23] wifi: brcmfmac: fix invalid address access when enabling SCAN log level

From: Sasha Levin
Date: Sun Oct 09 2022 - 20:34:45 EST


From: Wright Feng <wright.feng@xxxxxxxxxxx>

[ Upstream commit aa666b68e73fc06d83c070d96180b9010cf5a960 ]

The variable i is changed when setting random MAC address and causes
invalid address access when printing the value of pi->reqs[i]->reqid.

We replace reqs index with ri to fix the issue.

[ 136.726473] Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000000
[ 136.737365] Mem abort info:
[ 136.740172] ESR = 0x96000004
[ 136.743359] Exception class = DABT (current EL), IL = 32 bits
[ 136.749294] SET = 0, FnV = 0
[ 136.752481] EA = 0, S1PTW = 0
[ 136.755635] Data abort info:
[ 136.758514] ISV = 0, ISS = 0x00000004
[ 136.762487] CM = 0, WnR = 0
[ 136.765522] user pgtable: 4k pages, 48-bit VAs, pgdp = 000000005c4e2577
[ 136.772265] [0000000000000000] pgd=0000000000000000
[ 136.777160] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 136.782732] Modules linked in: brcmfmac(O) brcmutil(O) cfg80211(O) compat(O)
[ 136.789788] Process wificond (pid: 3175, stack limit = 0x00000000053048fb)
[ 136.796664] CPU: 3 PID: 3175 Comm: wificond Tainted: G O 4.19.42-00001-g531a5f5 #1
[ 136.805532] Hardware name: Freescale i.MX8MQ EVK (DT)
[ 136.810584] pstate: 60400005 (nZCv daif +PAN -UAO)
[ 136.815429] pc : brcmf_pno_config_sched_scans+0x6cc/0xa80 [brcmfmac]
[ 136.821811] lr : brcmf_pno_config_sched_scans+0x67c/0xa80 [brcmfmac]
[ 136.828162] sp : ffff00000e9a3880
[ 136.831475] x29: ffff00000e9a3890 x28: ffff800020543400
[ 136.836786] x27: ffff8000b1008880 x26: ffff0000012bf6a0
[ 136.842098] x25: ffff80002054345c x24: ffff800088d22400
[ 136.847409] x23: ffff0000012bf638 x22: ffff0000012bf6d8
[ 136.852721] x21: ffff8000aced8fc0 x20: ffff8000ac164400
[ 136.858032] x19: ffff00000e9a3946 x18: 0000000000000000
[ 136.863343] x17: 0000000000000000 x16: 0000000000000000
[ 136.868655] x15: ffff0000093f3b37 x14: 0000000000000050
[ 136.873966] x13: 0000000000003135 x12: 0000000000000000
[ 136.879277] x11: 0000000000000000 x10: ffff000009a61888
[ 136.884589] x9 : 000000000000000f x8 : 0000000000000008
[ 136.889900] x7 : 303a32303d726464 x6 : ffff00000a1f957d
[ 136.895211] x5 : 0000000000000000 x4 : ffff00000e9a3942
[ 136.900523] x3 : 0000000000000000 x2 : ffff0000012cead8
[ 136.905834] x1 : ffff0000012bf6d8 x0 : 0000000000000000
[ 136.911146] Call trace:
[ 136.913623] brcmf_pno_config_sched_scans+0x6cc/0xa80 [brcmfmac]
[ 136.919658] brcmf_pno_start_sched_scan+0xa4/0x118 [brcmfmac]
[ 136.925430] brcmf_cfg80211_sched_scan_start+0x80/0xe0 [brcmfmac]
[ 136.931636] nl80211_start_sched_scan+0x140/0x308 [cfg80211]
[ 136.937298] genl_rcv_msg+0x358/0x3f4
[ 136.940960] netlink_rcv_skb+0xb4/0x118
[ 136.944795] genl_rcv+0x34/0x48
[ 136.947935] netlink_unicast+0x264/0x300
[ 136.951856] netlink_sendmsg+0x2e4/0x33c
[ 136.955781] __sys_sendto+0x120/0x19c

Signed-off-by: Wright Feng <wright.feng@xxxxxxxxxxx>
Signed-off-by: Chi-hsien Lin <chi-hsien.lin@xxxxxxxxxxx>
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Signed-off-by: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220722115632.620681-4-alvin@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
.../net/wireless/broadcom/brcm80211/brcmfmac/pno.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
index ffa243e2e2d0..581a23549ee5 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
@@ -163,12 +163,12 @@ static int brcmf_pno_set_random(struct brcmf_if *ifp, struct brcmf_pno_info *pi)
struct brcmf_pno_macaddr_le pfn_mac;
u8 *mac_addr = NULL;
u8 *mac_mask = NULL;
- int err, i;
+ int err, i, ri;

- for (i = 0; i < pi->n_reqs; i++)
- if (pi->reqs[i]->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {
- mac_addr = pi->reqs[i]->mac_addr;
- mac_mask = pi->reqs[i]->mac_addr_mask;
+ for (ri = 0; ri < pi->n_reqs; ri++)
+ if (pi->reqs[ri]->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {
+ mac_addr = pi->reqs[ri]->mac_addr;
+ mac_mask = pi->reqs[ri]->mac_addr_mask;
break;
}

@@ -190,7 +190,7 @@ static int brcmf_pno_set_random(struct brcmf_if *ifp, struct brcmf_pno_info *pi)
pfn_mac.mac[0] |= 0x02;

brcmf_dbg(SCAN, "enabling random mac: reqid=%llu mac=%pM\n",
- pi->reqs[i]->reqid, pfn_mac.mac);
+ pi->reqs[ri]->reqid, pfn_mac.mac);
err = brcmf_fil_iovar_data_set(ifp, "pfn_macaddr", &pfn_mac,
sizeof(pfn_mac));
if (err)
--
2.35.1