From: Jiri Slaby <jslaby@suse.cz>
To: johannes.berg@intel.com
Cc: linux-kernel@vger.kernel.org, "Jiri Slaby" <jslaby@suse.cz>,
"Dieter Nützel" <Dieter@nuetzel-hh.de>,
"Emmanuel Grumbach" <emmanuel.grumbach@intel.com>,
"Luca Coelho" <luciano.coelho@intel.com>,
"Intel Linux Wireless" <linuxwifi@intel.com>,
"Kalle Valo" <kvalo@codeaurora.org>,
"David S. Miller" <davem@davemloft.net>,
"Jakub Kicinski" <kuba@kernel.org>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH] iwl: fix crash in iwl_dbg_tlv_alloc_trigger
Date: Fri, 12 Jun 2020 09:38:00 +0200 [thread overview]
Message-ID: <20200612073800.27742-1-jslaby@suse.cz> (raw)
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@suse.cz>
Reported-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Intel Linux Wireless <linuxwifi@intel.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
---
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 7987a288917b..27116c7d3f4f 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
@@ -271,6 +271,8 @@ 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;
@@ -283,10 +285,20 @@ 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,
--
2.27.0
next reply other threads:[~2020-06-12 7:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-12 7:38 Jiri Slaby [this message]
2020-06-12 7:55 ` [PATCH] iwl: fix crash in iwl_dbg_tlv_alloc_trigger Kalle Valo
2020-06-12 8:18 ` Luciano Coelho
2020-06-23 8:26 ` [PATCH] iwlwifi: " Kalle Valo
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