| Message ID | 20181124225707.12262-1-lyude@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | b72c51a58e6d63ef673ac96b8ab5bc98799c5f7b |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | brcmfmac: Fix out of bounds memory access during fw load | expand |
Lyude Paul <lyude@redhat.com> writes: > I ended up tracking down some rather nasty issues with f2fs (and other > filesystem modules) constantly crashing on my kernel down to a > combination of out of bounds memory accesses, one of which was coming > from brcmfmac during module load: > > [ 30.891382] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac4356-sdio for chip BCM4356/2 > [ 30.894437] ================================================================== > [ 30.901581] BUG: KASAN: global-out-of-bounds in brcmf_fw_alloc_request+0x42c/0x480 [brcmfmac] > [ 30.909935] Read of size 1 at addr ffff2000024865df by task kworker/6:2/387 > [ 30.916805] > [ 30.918261] CPU: 6 PID: 387 Comm: kworker/6:2 Tainted: G O 4.20.0-rc3Lyude-Test+ #19 > [ 30.927251] Hardware name: amlogic khadas-vim2/khadas-vim2, BIOS 2018.07-rc2-armbian 09/11/2018 > [ 30.935964] Workqueue: events brcmf_driver_register [brcmfmac] > [ 30.941641] Call trace: > [ 30.944058] dump_backtrace+0x0/0x3e8 > [ 30.947676] show_stack+0x14/0x20 > [ 30.950968] dump_stack+0x130/0x1c4 > [ 30.954406] print_address_description+0x60/0x25c > [ 30.959066] kasan_report+0x1b4/0x368 > [ 30.962683] __asan_report_load1_noabort+0x18/0x20 > [ 30.967547] brcmf_fw_alloc_request+0x42c/0x480 [brcmfmac] > [ 30.967639] brcmf_sdio_probe+0x163c/0x2050 [brcmfmac] > [ 30.978035] brcmf_ops_sdio_probe+0x598/0xa08 [brcmfmac] > [ 30.983254] sdio_bus_probe+0x190/0x398 > [ 30.983270] really_probe+0x2a0/0xa70 > [ 30.983296] driver_probe_device+0x1b4/0x2d8 > [ 30.994901] __driver_attach+0x200/0x280 > [ 30.994914] bus_for_each_dev+0x10c/0x1a8 > [ 30.994925] driver_attach+0x38/0x50 > [ 30.994935] bus_add_driver+0x330/0x608 > [ 30.994953] driver_register+0x140/0x388 > [ 31.013965] sdio_register_driver+0x74/0xa0 > [ 31.014076] brcmf_sdio_register+0x14/0x60 [brcmfmac] > [ 31.023177] brcmf_driver_register+0xc/0x18 [brcmfmac] > [ 31.023209] process_one_work+0x654/0x1080 > [ 31.032266] worker_thread+0x4f0/0x1308 > [ 31.032286] kthread+0x2a8/0x320 > [ 31.039254] ret_from_fork+0x10/0x1c > [ 31.039269] > [ 31.044226] The buggy address belongs to the variable: > [ 31.044351] brcmf_firmware_path+0x11f/0xfffffffffffd3b40 [brcmfmac] > [ 31.055601] > [ 31.057031] Memory state around the buggy address: > [ 31.061800] ffff200002486480: 04 fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 > [ 31.068983] ffff200002486500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > [ 31.068993] >ffff200002486580: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00 > [ 31.068999] ^ > [ 31.069017] ffff200002486600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > [ 31.096521] ffff200002486680: 00 00 00 00 00 00 00 00 00 00 00 00 fa fa fa fa > [ 31.096528] ================================================================== > [ 31.096533] Disabling lock debugging due to kernel taint > > It appears that when trying to determine the length of the string in the > alternate firmware path, we make the mistake of not handling the case > where the firmware path is empty correctly. Since strlen(mp_path) can > return 0, we'll end up accessing mp_path[-1] when the firmware_path > isn't provided through the module arguments. > > So, fix this by just setting the end char to '\0' by default, and only > changing it if we have a non-zero length. Additionally, use strnlen() > with BRCMF_FW_ALTPATH_LEN instead of strlen() just to be extra safe. > > Signed-off-by: Lyude Paul <lyude@redhat.com> > > Fixes: 2baa3aaee27f ("brcmfmac: introduce brcmf_fw_alloc_request() function") > Cc: Hante Meuleman <hante.meuleman@broadcom.com> > Cc: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com> > Cc: Franky Lin <franky.lin@broadcom.com> > Cc: Arend van Spriel <arend.vanspriel@broadcom.com> > Cc: Kalle Valo <kvalo@codeaurora.org> > Cc: Arend Van Spriel <arend.vanspriel@broadcom.com> > Cc: Himanshu Jha <himanshujha199640@gmail.com> > Cc: Dan Haab <dhaab@luxul.com> > Cc: Jia-Shyr Chuang <saint.chuang@cypress.com> > Cc: Ian Molton <ian@mnementh.co.uk> > Cc: <stable@vger.kernel.org> # v4.17+ > Signed-off-by: Lyude Paul <lyude@redhat.com> Lyude's s-o-b is twice, I can fix that. Arend, should I queue this to 4.20?
Lyude Paul <lyude@redhat.com> wrote: > I ended up tracking down some rather nasty issues with f2fs (and other > filesystem modules) constantly crashing on my kernel down to a > combination of out of bounds memory accesses, one of which was coming > from brcmfmac during module load: > > [ 30.891382] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac4356-sdio for chip BCM4356/2 > [ 30.894437] ================================================================== > [ 30.901581] BUG: KASAN: global-out-of-bounds in brcmf_fw_alloc_request+0x42c/0x480 [brcmfmac] > [ 30.909935] Read of size 1 at addr ffff2000024865df by task kworker/6:2/387 > [ 30.916805] > [ 30.918261] CPU: 6 PID: 387 Comm: kworker/6:2 Tainted: G O 4.20.0-rc3Lyude-Test+ #19 > [ 30.927251] Hardware name: amlogic khadas-vim2/khadas-vim2, BIOS 2018.07-rc2-armbian 09/11/2018 > [ 30.935964] Workqueue: events brcmf_driver_register [brcmfmac] > [ 30.941641] Call trace: > [ 30.944058] dump_backtrace+0x0/0x3e8 > [ 30.947676] show_stack+0x14/0x20 > [ 30.950968] dump_stack+0x130/0x1c4 > [ 30.954406] print_address_description+0x60/0x25c > [ 30.959066] kasan_report+0x1b4/0x368 > [ 30.962683] __asan_report_load1_noabort+0x18/0x20 > [ 30.967547] brcmf_fw_alloc_request+0x42c/0x480 [brcmfmac] > [ 30.967639] brcmf_sdio_probe+0x163c/0x2050 [brcmfmac] > [ 30.978035] brcmf_ops_sdio_probe+0x598/0xa08 [brcmfmac] > [ 30.983254] sdio_bus_probe+0x190/0x398 > [ 30.983270] really_probe+0x2a0/0xa70 > [ 30.983296] driver_probe_device+0x1b4/0x2d8 > [ 30.994901] __driver_attach+0x200/0x280 > [ 30.994914] bus_for_each_dev+0x10c/0x1a8 > [ 30.994925] driver_attach+0x38/0x50 > [ 30.994935] bus_add_driver+0x330/0x608 > [ 30.994953] driver_register+0x140/0x388 > [ 31.013965] sdio_register_driver+0x74/0xa0 > [ 31.014076] brcmf_sdio_register+0x14/0x60 [brcmfmac] > [ 31.023177] brcmf_driver_register+0xc/0x18 [brcmfmac] > [ 31.023209] process_one_work+0x654/0x1080 > [ 31.032266] worker_thread+0x4f0/0x1308 > [ 31.032286] kthread+0x2a8/0x320 > [ 31.039254] ret_from_fork+0x10/0x1c > [ 31.039269] > [ 31.044226] The buggy address belongs to the variable: > [ 31.044351] brcmf_firmware_path+0x11f/0xfffffffffffd3b40 [brcmfmac] > [ 31.055601] > [ 31.057031] Memory state around the buggy address: > [ 31.061800] ffff200002486480: 04 fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 > [ 31.068983] ffff200002486500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > [ 31.068993] >ffff200002486580: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00 > [ 31.068999] ^ > [ 31.069017] ffff200002486600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > [ 31.096521] ffff200002486680: 00 00 00 00 00 00 00 00 00 00 00 00 fa fa fa fa > [ 31.096528] ================================================================== > [ 31.096533] Disabling lock debugging due to kernel taint > > It appears that when trying to determine the length of the string in the > alternate firmware path, we make the mistake of not handling the case > where the firmware path is empty correctly. Since strlen(mp_path) can > return 0, we'll end up accessing mp_path[-1] when the firmware_path > isn't provided through the module arguments. > > So, fix this by just setting the end char to '\0' by default, and only > changing it if we have a non-zero length. Additionally, use strnlen() > with BRCMF_FW_ALTPATH_LEN instead of strlen() just to be extra safe. > > Fixes: 2baa3aaee27f ("brcmfmac: introduce brcmf_fw_alloc_request() function") > Cc: Hante Meuleman <hante.meuleman@broadcom.com> > Cc: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com> > Cc: Franky Lin <franky.lin@broadcom.com> > Cc: Arend van Spriel <arend.vanspriel@broadcom.com> > Cc: Kalle Valo <kvalo@codeaurora.org> > Cc: Arend Van Spriel <arend.vanspriel@broadcom.com> > Cc: Himanshu Jha <himanshujha199640@gmail.com> > Cc: Dan Haab <dhaab@luxul.com> > Cc: Jia-Shyr Chuang <saint.chuang@cypress.com> > Cc: Ian Molton <ian@mnementh.co.uk> > Cc: <stable@vger.kernel.org> # v4.17+ > Signed-off-by: Lyude Paul <lyude@redhat.com> Patch applied to wireless-drivers-next.git, thanks. b72c51a58e6d brcmfmac: Fix out of bounds memory access during fw load
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c index 9095b830ae4d..9927079a9ace 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c @@ -641,8 +641,9 @@ brcmf_fw_alloc_request(u32 chip, u32 chiprev, struct brcmf_fw_request *fwreq; char chipname[12]; const char *mp_path; + size_t mp_path_len; u32 i, j; - char end; + char end = '\0'; size_t reqsz; for (i = 0; i < table_size; i++) { @@ -667,7 +668,10 @@ brcmf_fw_alloc_request(u32 chip, u32 chiprev, mapping_table[i].fw_base, chipname); mp_path = brcmf_mp_global.firmware_path; - end = mp_path[strlen(mp_path) - 1]; + mp_path_len = strnlen(mp_path, BRCMF_FW_ALTPATH_LEN); + if (mp_path_len) + end = mp_path[mp_path_len - 1]; + fwreq->n_items = n_fwnames; for (j = 0; j < n_fwnames; j++) {