diff options
| author | Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> | 2015-12-04 01:45:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-22 20:54:13 -0800 |
| commit | 8fa4abd57ad4ef9b2ff9beda2eb29368ae10ae9e (patch) | |
| tree | 723cfce1abb8956751aad79a5ce073eb78a89df0 | |
| parent | bc8f79b522b57ca79a676615003d85b08162ff5a (diff) | |
sh_eth: fix kernel oops in skb_put()
[ Upstream commit 248be83dcb3feb3f6332eb3d010a016402138484 ]
In a low memory situation the following kernel oops occurs:
Unable to handle kernel NULL pointer dereference at virtual address 00000050
pgd = 8490c000
[00000050] *pgd=4651e831, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 Not tainted (3.4-at16 #9)
PC is at skb_put+0x10/0x98
LR is at sh_eth_poll+0x2c8/0xa10
pc : [<8035f780>] lr : [<8028bf50>] psr: 60000113
sp : 84eb1a90 ip : 84eb1ac8 fp : 84eb1ac4
r10: 0000003f r9 : 000005ea r8 : 00000000
r7 : 00000000 r6 : 940453b0 r5 : 00030000 r4 : 9381b180
r3 : 00000000 r2 : 00000000 r1 : 000005ea r0 : 00000000
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 10c53c7d Table: 4248c059 DAC: 00000015
Process klogd (pid: 2046, stack limit = 0x84eb02e8)
[...]
This is because netdev_alloc_skb() fails and 'mdp->rx_skbuff[entry]' is left
NULL but sh_eth_rx() later uses it without checking. Add such check...
Reported-by: Yasushi SHOJI <yashi@atmark-techno.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/ethernet/renesas/sh_eth.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index 7fb244f565b2..13463c4acc86 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1481,6 +1481,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota) if (mdp->cd->shift_rd0) desc_status >>= 16; + skb = mdp->rx_skbuff[entry]; if (desc_status & (RD_RFS1 | RD_RFS2 | RD_RFS3 | RD_RFS4 | RD_RFS5 | RD_RFS6 | RD_RFS10)) { ndev->stats.rx_errors++; @@ -1496,12 +1497,11 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota) ndev->stats.rx_missed_errors++; if (desc_status & RD_RFS10) ndev->stats.rx_over_errors++; - } else { + } else if (skb) { if (!mdp->cd->hw_swap) sh_eth_soft_swap( phys_to_virt(ALIGN(rxdesc->addr, 4)), pkt_len + 2); - skb = mdp->rx_skbuff[entry]; mdp->rx_skbuff[entry] = NULL; if (mdp->cd->rpadir) skb_reserve(skb, NET_IP_ALIGN); |