This fixes: 1) Getting STA info with newer firmwares 2) Getting DMI / UEFI / OF data 3) Possible memory corruption in firmware loading code Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
		
			
				
	
	
		
			111 lines
		
	
	
		
			5.0 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			111 lines
		
	
	
		
			5.0 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From b72c51a58e6d63ef673ac96b8ab5bc98799c5f7b Mon Sep 17 00:00:00 2001
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From: Lyude Paul <lyude@redhat.com>
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Date: Sat, 24 Nov 2018 17:57:05 -0500
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Subject: [PATCH] brcmfmac: Fix out of bounds memory access during fw load
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I ended up tracking down some rather nasty issues with f2fs (and other
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filesystem modules) constantly crashing on my kernel down to a
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combination of out of bounds memory accesses, one of which was coming
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from brcmfmac during module load:
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[   30.891382] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac4356-sdio for chip BCM4356/2
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[   30.894437] ==================================================================
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[   30.901581] BUG: KASAN: global-out-of-bounds in brcmf_fw_alloc_request+0x42c/0x480 [brcmfmac]
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[   30.909935] Read of size 1 at addr ffff2000024865df by task kworker/6:2/387
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[   30.916805]
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[   30.918261] CPU: 6 PID: 387 Comm: kworker/6:2 Tainted: G           O      4.20.0-rc3Lyude-Test+ #19
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[   30.927251] Hardware name: amlogic khadas-vim2/khadas-vim2, BIOS 2018.07-rc2-armbian 09/11/2018
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[   30.935964] Workqueue: events brcmf_driver_register [brcmfmac]
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[   30.941641] Call trace:
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[   30.944058]  dump_backtrace+0x0/0x3e8
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[   30.947676]  show_stack+0x14/0x20
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[   30.950968]  dump_stack+0x130/0x1c4
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[   30.954406]  print_address_description+0x60/0x25c
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[   30.959066]  kasan_report+0x1b4/0x368
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[   30.962683]  __asan_report_load1_noabort+0x18/0x20
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[   30.967547]  brcmf_fw_alloc_request+0x42c/0x480 [brcmfmac]
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[   30.967639]  brcmf_sdio_probe+0x163c/0x2050 [brcmfmac]
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[   30.978035]  brcmf_ops_sdio_probe+0x598/0xa08 [brcmfmac]
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[   30.983254]  sdio_bus_probe+0x190/0x398
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[   30.983270]  really_probe+0x2a0/0xa70
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[   30.983296]  driver_probe_device+0x1b4/0x2d8
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[   30.994901]  __driver_attach+0x200/0x280
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[   30.994914]  bus_for_each_dev+0x10c/0x1a8
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[   30.994925]  driver_attach+0x38/0x50
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[   30.994935]  bus_add_driver+0x330/0x608
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[   30.994953]  driver_register+0x140/0x388
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[   31.013965]  sdio_register_driver+0x74/0xa0
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[   31.014076]  brcmf_sdio_register+0x14/0x60 [brcmfmac]
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[   31.023177]  brcmf_driver_register+0xc/0x18 [brcmfmac]
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[   31.023209]  process_one_work+0x654/0x1080
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[   31.032266]  worker_thread+0x4f0/0x1308
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[   31.032286]  kthread+0x2a8/0x320
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[   31.039254]  ret_from_fork+0x10/0x1c
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[   31.039269]
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[   31.044226] The buggy address belongs to the variable:
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[   31.044351]  brcmf_firmware_path+0x11f/0xfffffffffffd3b40 [brcmfmac]
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[   31.055601]
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[   31.057031] Memory state around the buggy address:
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[   31.061800]  ffff200002486480: 04 fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
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[   31.068983]  ffff200002486500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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[   31.068993] >ffff200002486580: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00
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[   31.068999]                                                     ^
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[   31.069017]  ffff200002486600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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[   31.096521]  ffff200002486680: 00 00 00 00 00 00 00 00 00 00 00 00 fa fa fa fa
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[   31.096528] ==================================================================
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[   31.096533] Disabling lock debugging due to kernel taint
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It appears that when trying to determine the length of the string in the
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alternate firmware path, we make the mistake of not handling the case
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where the firmware path is empty correctly. Since strlen(mp_path) can
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return 0, we'll end up accessing mp_path[-1] when the firmware_path
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isn't provided through the module arguments.
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So, fix this by just setting the end char to '\0' by default, and only
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changing it if we have a non-zero length. Additionally, use strnlen()
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with BRCMF_FW_ALTPATH_LEN instead of strlen() just to be extra safe.
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Fixes: 2baa3aaee27f ("brcmfmac: introduce brcmf_fw_alloc_request() function")
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Cc: Hante Meuleman <hante.meuleman@broadcom.com>
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Cc: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
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Cc: Franky Lin <franky.lin@broadcom.com>
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Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
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Cc: Kalle Valo <kvalo@codeaurora.org>
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Cc: Arend Van Spriel <arend.vanspriel@broadcom.com>
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Cc: Himanshu Jha <himanshujha199640@gmail.com>
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Cc: Dan Haab <dhaab@luxul.com>
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Cc: Jia-Shyr Chuang <saint.chuang@cypress.com>
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Cc: Ian Molton <ian@mnementh.co.uk>
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Cc: <stable@vger.kernel.org> # v4.17+
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Signed-off-by: Lyude Paul <lyude@redhat.com>
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Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
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---
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 .../net/wireless/broadcom/brcm80211/brcmfmac/firmware.c   | 8 ++++++--
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 1 file changed, 6 insertions(+), 2 deletions(-)
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--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
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+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
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@@ -708,8 +708,9 @@ brcmf_fw_alloc_request(u32 chip, u32 chi
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 	struct brcmf_fw_request *fwreq;
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 	char chipname[12];
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 	const char *mp_path;
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+	size_t mp_path_len;
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 	u32 i, j;
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-	char end;
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+	char end = '\0';
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 	size_t reqsz;
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 	for (i = 0; i < table_size; i++) {
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@@ -734,7 +735,10 @@ brcmf_fw_alloc_request(u32 chip, u32 chi
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 		   mapping_table[i].fw_base, chipname);
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 	mp_path = brcmf_mp_global.firmware_path;
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-	end = mp_path[strlen(mp_path) - 1];
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+	mp_path_len = strnlen(mp_path, BRCMF_FW_ALTPATH_LEN);
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+	if (mp_path_len)
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+		end = mp_path[mp_path_len - 1];
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+
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 	fwreq->n_items = n_fwnames;
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 	for (j = 0; j < n_fwnames; j++) {
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