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minskMedveKalle Valo
minskMedve
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Kalle Valo
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wifi: brcmfmac: Check the count value of channel spec to prevent out-of-bounds reads
This patch fixes slab-out-of-bounds reads in brcmfmac that occur in brcmf_construct_chaninfo() and brcmf_enable_bw40_2g() when the count value of channel specifications provided by the device is greater than the length of 'list->element[]', decided by the size of the 'list' allocated with kzalloc(). The patch adds checks that make the functions free the buffer and return -EINVAL if that is the case. Note that the negative return is handled by the caller, brcmf_setup_wiphybands() or brcmf_cfg80211_attach(). Found by a modified version of syzkaller. Crash Report from brcmf_construct_chaninfo(): ================================================================== BUG: KASAN: slab-out-of-bounds in brcmf_setup_wiphybands+0x1238/0x1430 Read of size 4 at addr ffff888115f24600 by task kworker/0:2/1896 CPU: 0 PID: 1896 Comm: kworker/0:2 Tainted: G W O 5.14.0+ #132 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x57/0x7d print_address_description.constprop.0.cold+0x93/0x334 kasan_report.cold+0x83/0xdf brcmf_setup_wiphybands+0x1238/0x1430 brcmf_cfg80211_attach+0x2118/0x3fd0 brcmf_attach+0x389/0xd40 brcmf_usb_probe+0x12de/0x1690 usb_probe_interface+0x25f/0x710 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_set_configuration+0x984/0x1770 usb_generic_driver_probe+0x69/0x90 usb_probe_device+0x9c/0x220 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_new_device.cold+0x463/0xf66 hub_event+0x10d5/0x3330 process_one_work+0x873/0x13e0 worker_thread+0x8b/0xd10 kthread+0x379/0x450 ret_from_fork+0x1f/0x30 Allocated by task 1896: kasan_save_stack+0x1b/0x40 __kasan_kmalloc+0x7c/0x90 kmem_cache_alloc_trace+0x19e/0x330 brcmf_setup_wiphybands+0x290/0x1430 brcmf_cfg80211_attach+0x2118/0x3fd0 brcmf_attach+0x389/0xd40 brcmf_usb_probe+0x12de/0x1690 usb_probe_interface+0x25f/0x710 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_set_configuration+0x984/0x1770 usb_generic_driver_probe+0x69/0x90 usb_probe_device+0x9c/0x220 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_new_device.cold+0x463/0xf66 hub_event+0x10d5/0x3330 process_one_work+0x873/0x13e0 worker_thread+0x8b/0xd10 kthread+0x379/0x450 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff888115f24000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1536 bytes inside of 2048-byte region [ffff888115f24000, ffff888115f24800) Memory state around the buggy address: ffff888115f24500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888115f24580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888115f24600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888115f24680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888115f24700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Crash Report from brcmf_enable_bw40_2g(): ================================================================== BUG: KASAN: slab-out-of-bounds in brcmf_cfg80211_attach+0x3d11/0x3fd0 Read of size 4 at addr ffff888103787600 by task kworker/0:2/1896 CPU: 0 PID: 1896 Comm: kworker/0:2 Tainted: G W O 5.14.0+ #132 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x57/0x7d print_address_description.constprop.0.cold+0x93/0x334 kasan_report.cold+0x83/0xdf brcmf_cfg80211_attach+0x3d11/0x3fd0 brcmf_attach+0x389/0xd40 brcmf_usb_probe+0x12de/0x1690 usb_probe_interface+0x25f/0x710 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_set_configuration+0x984/0x1770 usb_generic_driver_probe+0x69/0x90 usb_probe_device+0x9c/0x220 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_new_device.cold+0x463/0xf66 hub_event+0x10d5/0x3330 process_one_work+0x873/0x13e0 worker_thread+0x8b/0xd10 kthread+0x379/0x450 ret_from_fork+0x1f/0x30 Allocated by task 1896: kasan_save_stack+0x1b/0x40 __kasan_kmalloc+0x7c/0x90 kmem_cache_alloc_trace+0x19e/0x330 brcmf_cfg80211_attach+0x3302/0x3fd0 brcmf_attach+0x389/0xd40 brcmf_usb_probe+0x12de/0x1690 usb_probe_interface+0x25f/0x710 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_set_configuration+0x984/0x1770 usb_generic_driver_probe+0x69/0x90 usb_probe_device+0x9c/0x220 really_probe+0x1be/0xa90 __driver_probe_device+0x2ab/0x460 driver_probe_device+0x49/0x120 __device_attach_driver+0x18a/0x250 bus_for_each_drv+0x123/0x1a0 __device_attach+0x207/0x330 bus_probe_device+0x1a2/0x260 device_add+0xa61/0x1ce0 usb_new_device.cold+0x463/0xf66 hub_event+0x10d5/0x3330 process_one_work+0x873/0x13e0 worker_thread+0x8b/0xd10 kthread+0x379/0x450 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff888103787000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1536 bytes inside of 2048-byte region [ffff888103787000, ffff888103787800) Memory state around the buggy address: ffff888103787500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888103787580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888103787600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888103787680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888103787700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Reported-by: Dokyung Song <[email protected]> Reported-by: Jisoo Jang <[email protected]> Reported-by: Minsuk Kang <[email protected]> Reviewed-by: Arend van Spriel <[email protected]> Signed-off-by: Minsuk Kang <[email protected]> Signed-off-by: Kalle Valo <[email protected]> Link: https://lore.kernel.org/r/[email protected]
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  • drivers/net/wireless/broadcom/brcm80211/brcmfmac

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‎drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c

Lines changed: 17 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -101,6 +101,9 @@
101101
#define BRCMF_ASSOC_PARAMS_FIXED_SIZE \
102102
(sizeof(struct brcmf_assoc_params_le) - sizeof(u16))
103103

104+
#define BRCMF_MAX_CHANSPEC_LIST \
105+
(BRCMF_DCMD_MEDLEN / sizeof(__le32) - 1)
106+
104107
struct brcmf_dump_survey {
105108
u32 obss;
106109
u32 ibss;
@@ -6840,6 +6843,13 @@ static int brcmf_construct_chaninfo(struct brcmf_cfg80211_info *cfg,
68406843
band->channels[i].flags = IEEE80211_CHAN_DISABLED;
68416844

68426845
total = le32_to_cpu(list->count);
6846+
if (total > BRCMF_MAX_CHANSPEC_LIST) {
6847+
bphy_err(drvr, "Invalid count of channel Spec. (%u)\n",
6848+
total);
6849+
err = -EINVAL;
6850+
goto fail_pbuf;
6851+
}
6852+
68436853
for (i = 0; i < total; i++) {
68446854
ch.chspec = (u16)le32_to_cpu(list->element[i]);
68456855
cfg->d11inf.decchspec(&ch);
@@ -6985,6 +6995,13 @@ static int brcmf_enable_bw40_2g(struct brcmf_cfg80211_info *cfg)
69856995
band = cfg_to_wiphy(cfg)->bands[NL80211_BAND_2GHZ];
69866996
list = (struct brcmf_chanspec_list *)pbuf;
69876997
num_chan = le32_to_cpu(list->count);
6998+
if (num_chan > BRCMF_MAX_CHANSPEC_LIST) {
6999+
bphy_err(drvr, "Invalid count of channel Spec. (%u)\n",
7000+
num_chan);
7001+
kfree(pbuf);
7002+
return -EINVAL;
7003+
}
7004+
69887005
for (i = 0; i < num_chan; i++) {
69897006
ch.chspec = (u16)le32_to_cpu(list->element[i]);
69907007
cfg->d11inf.decchspec(&ch);

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