[PATCH 5.7 095/120] iwlwifi: fix crash in iwl_dbg_tlv_alloc_trigger
From: Greg Kroah-Hartman
Date: Mon Aug 03 2020 - 08:26:33 EST
From: Jiri Slaby <jslaby@xxxxxxx>
[ Upstream commit ea0cca61d628662e4a1b26c77c7646f9a0257069 ]
The tlv passed to iwl_dbg_tlv_alloc_trigger comes from a loaded firmware
file. The memory can be marked as read-only as firmware could be
shared. In anyway, writing to this memory is not expected. So,
iwl_dbg_tlv_alloc_trigger can crash now:
BUG: unable to handle page fault for address: ffffae2c01bfa794
PF: supervisor write access in kernel mode
PF: error_code(0x0003) - permissions violation
PGD 107d51067 P4D 107d51067 PUD 107d52067 PMD 659ad2067 PTE 8000000662298161
CPU: 2 PID: 161 Comm: kworker/2:1 Not tainted 5.7.0-3.gad96a07-default #1 openSUSE Tumbleweed (unreleased)
RIP: 0010:iwl_dbg_tlv_alloc_trigger+0x25/0x60 [iwlwifi]
Code: eb f2 0f 1f 00 66 66 66 66 90 83 7e 04 33 48 89 f8 44 8b 46 10 48 89 f7 76 40 41 8d 50 ff 83 fa 19 77 23 8b 56 20 85 d2 75 07 <c7> 46 20 ff ff ff ff 4b 8d 14 40 48 c1 e2 04 48 8d b4 10 00 05 00
RSP: 0018:ffffae2c00417ce8 EFLAGS: 00010246
RAX: ffff8f0522334018 RBX: ffff8f0522334018 RCX: ffffffffc0fc26c0
RDX: 0000000000000000 RSI: ffffae2c01bfa774 RDI: ffffae2c01bfa774
RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000034 R11: ffffae2c01bfa77c R12: ffff8f0522334230
R13: 0000000001000009 R14: ffff8f0523fdbc00 R15: ffff8f051f395800
FS: 0000000000000000(0000) GS:ffff8f0527c80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffae2c01bfa794 CR3: 0000000389eba000 CR4: 00000000000006e0
Call Trace:
iwl_dbg_tlv_alloc+0x79/0x120 [iwlwifi]
iwl_parse_tlv_firmware.isra.0+0x57d/0x1550 [iwlwifi]
iwl_req_fw_callback+0x3f8/0x6a0 [iwlwifi]
request_firmware_work_func+0x47/0x90
process_one_work+0x1e3/0x3b0
worker_thread+0x46/0x340
kthread+0x115/0x140
ret_from_fork+0x1f/0x40
As can be seen, write bit is not set in the PTE. Read of
trig->occurrences succeeds in iwl_dbg_tlv_alloc_trigger, but
trig->occurrences = cpu_to_le32(-1); fails there, obviously.
This is likely because we (at SUSE) use compressed firmware and that is
marked as RO after decompression (see fw_map_paged_buf).
Fix it by creating a temporary buffer in case we need to change the
memory.
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Reported-by: Dieter Nützel <Dieter@xxxxxxxxxxxxx>
Tested-by: Dieter Nützel <Dieter@xxxxxxxxxxxxx>
Cc: Johannes Berg <johannes.berg@xxxxxxxxx>
Cc: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Cc: Luca Coelho <luciano.coelho@xxxxxxxxx>
Cc: Intel Linux Wireless <linuxwifi@xxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200612073800.27742-1-jslaby@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
index bf2f00b892140..85b132a77787d 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
@@ -263,6 +263,8 @@ static int iwl_dbg_tlv_alloc_trigger(struct iwl_trans *trans,
{
struct iwl_fw_ini_trigger_tlv *trig = (void *)tlv->data;
u32 tp = le32_to_cpu(trig->time_point);
+ struct iwl_ucode_tlv *dup = NULL;
+ int ret;
if (le32_to_cpu(tlv->length) < sizeof(*trig))
return -EINVAL;
@@ -275,10 +277,20 @@ static int iwl_dbg_tlv_alloc_trigger(struct iwl_trans *trans,
return -EINVAL;
}
- if (!le32_to_cpu(trig->occurrences))
+ if (!le32_to_cpu(trig->occurrences)) {
+ dup = kmemdup(tlv, sizeof(*tlv) + le32_to_cpu(tlv->length),
+ GFP_KERNEL);
+ if (!dup)
+ return -ENOMEM;
+ trig = (void *)dup->data;
trig->occurrences = cpu_to_le32(-1);
+ tlv = dup;
+ }
+
+ ret = iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].trig_list);
+ kfree(dup);
- return iwl_dbg_tlv_add(tlv, &trans->dbg.time_point[tp].trig_list);
+ return ret;
}
static int (*dbg_tlv_alloc[])(struct iwl_trans *trans,
--
2.25.1