4.3-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
commit 7f109f7cc37108cba7243bc832988525b0d85909 upstream.
When vrf's ->newlink is called, if register_netdevice() fails then it
does free_netdev(), but that's also done by rtnl_newlink() so a second
free happens and memory gets corrupted, to reproduce execute the
following line a couple of times (1 - 5 usually is enough):
$ for i in `seq 1 5`; do ip link add vrf: type vrf table 1; done;
This works because we fail in register_netdevice() because of the wrong
name "vrf:".
And here's a trace of one crash:
[ 28.792157] ------------[ cut here ]------------
[ 28.792407] kernel BUG at fs/namei.c:246!
[ 28.792608] invalid opcode: 0000 [#1] SMP
[ 28.793240] Modules linked in: vrf nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace sunrpc crct10dif_pclmul crc32_pclmul crc32c_intel qxl drm_kms_helper ttm drm aesni_intel aes_x86_64 psmouse glue_helper lrw evdev gf128mul i2c_piix4 ablk_helper cryptd ppdev parport_pc parport serio_raw pcspkr virtio_balloon virtio_console i2c_core acpi_cpufreq button 9pnet_virtio 9p 9pnet fscache ipv6 autofs4 ext4 crc16 mbcache jbd2 virtio_blk virtio_net sg sr_mod cdrom ata_generic ehci_pci uhci_hcd ehci_hcd e1000 usbcore usb_common ata_piix libata virtio_pci virtio_ring virtio scsi_mod floppy
[ 28.796016] CPU: 0 PID: 1148 Comm: ld-linux-x86-64 Not tainted
4.4.0-rc1+ #24
[ 28.796016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
[ 28.796016] task: ffff8800352561c0 ti: ffff88003592c000 task.ti: ffff88003592c000
[ 28.796016] RIP: 0010:[<ffffffff812187b3>] [<ffffffff812187b3>] putname+0x43/0x60
[ 28.796016] RSP: 0018:ffff88003592fe88 EFLAGS: 00010246
[ 28.796016] RAX: 0000000000000000 RBX: ffff8800352561c0 RCX: 0000000000000001
[ 28.796016] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88003784f000
[ 28.796016] RBP: ffff88003592ff08 R08: 0000000000000001 R09: 0000000000000000
[ 28.796016] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
[ 28.796016] R13: 000000000000047c R14: ffff88003784f000 R15: ffff8800358c4a00
[ 28.796016] FS: 0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
[ 28.796016] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 28.796016] CR2: 00007ffd583bc2d9 CR3: 0000000035a99000 CR4: 00000000000406f0
[ 28.796016] Stack:
[ 28.796016] ffffffff8121045d ffffffff812102d3 ffff8800352561c0 ffff880035a91660
[ 28.796016] ffff8800008a9880 0000000000000000 ffffffff81a49940 00ffffff81218684
[ 28.796016] ffff8800352561c0 000000000000047c 0000000000000000 ffff880035b36d80
[ 28.796016] Call Trace:
[ 28.796016] [<ffffffff8121045d>] ? do_execveat_common.isra.34+0x74d/0x930
[ 28.796016] [<ffffffff812102d3>] ? do_execveat_common.isra.34+0x5c3/0x930
[ 28.796016] [<ffffffff8121066c>] do_execve+0x2c/0x30
[ 28.796016] [<ffffffff810939a0>] call_usermodehelper_exec_async+0xf0/0x140
[ 28.796016] [<ffffffff810938b0>] ? umh_complete+0x40/0x40
[ 28.796016] [<ffffffff815cb1af>] ret_from_fork+0x3f/0x70
[ 28.796016] Code: 48 8d 47 1c 48 89 e5 53 48 8b 37 48 89 fb 48 39 c6 74 1a 48 8b 3d 7e e9 8f 00 e8 49 fa fc ff 48 89 df e8 f1 01 fd ff 5b 5d f3 c3 <0f> 0b 48 89 fe 48 8b 3d 61 e9 8f 00 e8 2c fa fc ff 5b 5d eb e9
[ 28.796016] RIP [<ffffffff812187b3>] putname+0x43/0x60
[ 28.796016] RSP <ffff88003592fe88>
Fixes: 193125dbd8eb ("net: Introduce VRF device driver")
Signed-off-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Acked-by: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: For 4.3, retain the kfree() on failure]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
Acked-by: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/vrf.c | 1 -
1 file changed, 1 deletion(-)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -608,7 +608,6 @@ static int vrf_newlink(struct net *src_n
out_fail:
kfree(vrf_ptr);
- free_netdev(dev);
return err;
}
--
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