diff options
| author | Zekun Shen <bruceshenzk@gmail.com> | 2021-11-18 16:42:47 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-11-19 11:54:34 +0000 |
| commit | 0f296e782f21dc1c55475a3c107ac68ab09cc1cf (patch) | |
| tree | 4ddb23ef1cddaeba8594b575979725c8859a8528 | |
| parent | 6a405f6c372d14707b87d3097b361b69899a26c8 (diff) | |
| download | linux-0f296e782f21dc1c55475a3c107ac68ab09cc1cf.tar.bz2 | |
stmmac_pci: Fix underflow size in stmmac_rx
This bug report came up when we were testing the device driver
by fuzzing. It shows that buf1_len can get underflowed and be
0xfffffffc (4294967292).
This bug is triggerable with a compromised/malfunctioning device.
We found the bug through QEMU emulation tested the patch with
emulation. We did NOT test it on real hardware.
Attached is the bug report by fuzzing.
BUG: KASAN: use-after-free in stmmac_napi_poll_rx+0x1c08/0x36e0 [stmmac]
Read of size 4294967292 at addr ffff888016358000 by task ksoftirqd/0/9
CPU: 0 PID: 9 Comm: ksoftirqd/0 Tainted: G W 5.6.0 #1
Call Trace:
dump_stack+0x76/0xa0
print_address_description.constprop.0+0x16/0x200
? stmmac_napi_poll_rx+0x1c08/0x36e0 [stmmac]
? stmmac_napi_poll_rx+0x1c08/0x36e0 [stmmac]
__kasan_report.cold+0x37/0x7c
? stmmac_napi_poll_rx+0x1c08/0x36e0 [stmmac]
kasan_report+0xe/0x20
check_memory_region+0x15a/0x1d0
memcpy+0x20/0x50
stmmac_napi_poll_rx+0x1c08/0x36e0 [stmmac]
? stmmac_suspend+0x850/0x850 [stmmac]
? __next_timer_interrupt+0xba/0xf0
net_rx_action+0x363/0xbd0
? call_timer_fn+0x240/0x240
? __switch_to_asm+0x40/0x70
? napi_busy_loop+0x520/0x520
? __schedule+0x839/0x15a0
__do_softirq+0x18c/0x634
? takeover_tasklets+0x5f0/0x5f0
run_ksoftirqd+0x15/0x20
smpboot_thread_fn+0x2f1/0x6b0
? smpboot_unregister_percpu_thread+0x160/0x160
? __kthread_parkme+0x80/0x100
? smpboot_unregister_percpu_thread+0x160/0x160
kthread+0x2b5/0x3b0
? kthread_create_on_node+0xd0/0xd0
ret_from_fork+0x22/0x40
Reported-by: Brendan Dolan-Gavitt <brendandg@nyu.edu>
Signed-off-by: Zekun Shen <bruceshenzk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 2eb284576336..19bc86f2092f 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -5161,12 +5161,13 @@ read_again: if (likely(!(status & rx_not_ls)) && (likely(priv->synopsys_id >= DWMAC_CORE_4_00) || unlikely(status != llc_snap))) { - if (buf2_len) + if (buf2_len) { buf2_len -= ETH_FCS_LEN; - else + len -= ETH_FCS_LEN; + } else if (buf1_len) { buf1_len -= ETH_FCS_LEN; - - len -= ETH_FCS_LEN; + len -= ETH_FCS_LEN; + } } if (!skb) { |