On Fri, 2020-06-12 at 10:55 +0300, Kalle Valo wrote: > Jiri Slaby <jslaby@xxxxxxx> writes: > > > 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 > > --- > > drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 16 ++++++++++++++-- > > The prefix should be "iwlwifi: ", I can fix that. > > Luca, should I take this to wireless-drivers? Yeah, this looks good. Thanks, Jiri! And yes, Kalle, please apply it directly to w-d. Thank you! -- Cheers, Luca.
