| Message ID | 1498048.4g9dLWgJuk@wasted.cogentembedded.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Date: Fri, 04 Dec 2015 01:45:40 +0300 > 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> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello. On 12/6/2015 1:46 AM, David Miller wrote: >> 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> > Applied. Could you also queue this for the stable kernels? MBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Date: Sat, 12 Dec 2015 18:17:45 +0300 > Hello. > > On 12/6/2015 1:46 AM, David Miller wrote: > >>> 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> > >> Applied. > > Could you also queue this for the stable kernels? Done. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: net/drivers/net/ethernet/renesas/sh_eth.c =================================================================== --- net.orig/drivers/net/ethernet/renesas/sh_eth.c +++ net/drivers/net/ethernet/renesas/sh_eth.c @@ -1462,6 +1462,7 @@ static int sh_eth_rx(struct net_device * 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++; @@ -1477,12 +1478,11 @@ static int sh_eth_rx(struct net_device * 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);
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> --- The patch is against Dave Miller's 'net.git' repo. Changes in version 3: - refreshed the patch; - reformatted the changelog; - removed [RFT] from the subject. Changes in version 2: - moved reading 'mdp->rx_skbuff[entry]' earlier to avoid *goto*. drivers/net/ethernet/renesas/sh_eth.c | 4 ++-- drivers/net/ethernet/renesas/sh_eth.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html