| Message ID | cb08146799e6e0a9660ad2a384f76795858b934b.1521154629.git.dcaratti@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | net/sched: fix NULL dereference in the error path of .init() | expand |
Fri, Mar 16, 2018 at 12:00:54AM CET, dcaratti@redhat.com wrote: >when the following command > > # tc action add action csum udp continue index 100 > >is run for the first time, and tcf_csum_init() fails allocating struct >tcf_csum, tcf_csum_cleanup() calls kfree_rcu(NULL,...). This causes the >following error: > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 > IP: __call_rcu+0x23/0x2b0 > PGD 80000000740b4067 P4D 80000000740b4067 PUD 32e7f067 PMD 0 > Oops: 0002 [#1] SMP PTI > Modules linked in: act_csum(E) act_vlan ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 mbcache jbd2 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic pcbc snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer aesni_intel crypto_simd glue_helper cryptd snd joydev pcspkr virtio_balloon i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm virtio_blk drm virtio_net virtio_console ata_piix crc32c_intel libata virtio_pci serio_raw i2c_core virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_vlan] > CPU: 2 PID: 5763 Comm: tc Tainted: G E 4.16.0-rc4.act_vlan.orig+ #403 > Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 > RIP: 0010:__call_rcu+0x23/0x2b0 > RSP: 0018:ffffb275803e77c0 EFLAGS: 00010246 > RAX: ffffffffc057b080 RBX: ffff9674bc6f5240 RCX: 00000000ffffffff > RDX: ffffffff928a5f00 RSI: 0000000000000008 RDI: 0000000000000008 > RBP: 0000000000000008 R08: 0000000000000001 R09: 0000000000000044 > R10: 0000000000000220 R11: ffff9674b9ab4821 R12: 0000000000000000 > R13: ffffffff928a5f00 R14: 0000000000000000 R15: 0000000000000001 > FS: 00007fa6368d8740(0000) GS:ffff9674bfd00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000010 CR3: 0000000073dec001 CR4: 00000000001606e0 > Call Trace: > __tcf_idr_release+0x79/0xf0 > tcf_csum_init+0xfb/0x180 [act_csum] > tcf_action_init_1+0x2cc/0x430 > tcf_action_init+0xd3/0x1b0 > tc_ctl_action+0x18b/0x240 > rtnetlink_rcv_msg+0x29c/0x310 > ? _cond_resched+0x15/0x30 > ? __kmalloc_node_track_caller+0x1b9/0x270 > ? rtnl_calcit.isra.28+0x100/0x100 > netlink_rcv_skb+0xd2/0x110 > netlink_unicast+0x17c/0x230 > netlink_sendmsg+0x2cd/0x3c0 > sock_sendmsg+0x30/0x40 > ___sys_sendmsg+0x27a/0x290 > ? filemap_map_pages+0x34a/0x3a0 > ? __handle_mm_fault+0xbfd/0xe20 > __sys_sendmsg+0x51/0x90 > do_syscall_64+0x6e/0x1a0 > entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > RIP: 0033:0x7fa635ce9ba0 > RSP: 002b:00007ffc185b0fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 00007ffc185b10f0 RCX: 00007fa635ce9ba0 > RDX: 0000000000000000 RSI: 00007ffc185b1040 RDI: 0000000000000003 > RBP: 000000005aaa85e0 R08: 0000000000000002 R09: 0000000000000000 > R10: 00007ffc185b0a20 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007ffc185b1104 R14: 0000000000000001 R15: 0000000000669f60 > Code: 5d e9 42 da ff ff 66 90 0f 1f 44 00 00 41 57 41 56 41 55 49 89 d5 41 54 55 48 89 fd 53 48 83 ec 08 40 f6 c7 07 0f 85 19 02 00 00 <48> 89 75 08 48 c7 45 00 00 00 00 00 9c 58 0f 1f 44 00 00 49 89 > RIP: __call_rcu+0x23/0x2b0 RSP: ffffb275803e77c0 > CR2: 0000000000000010 > >fix this in tcf_csum_cleanup(), ensuring that kfree_rcu(param, ...) is >called only when param is not NULL. > >Fixes: 9c5f69bbd75a ("net/sched: act_csum: don't use spinlock in the fast path") >Signed-off-by: Davide Caratti <dcaratti@redhat.com> Acked-by: Jiri Pirko <jiri@mellanox.com>
diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c index 24b2e8e681cf..2a5c8fd860cf 100644 --- a/net/sched/act_csum.c +++ b/net/sched/act_csum.c @@ -626,7 +626,8 @@ static void tcf_csum_cleanup(struct tc_action *a) struct tcf_csum_params *params; params = rcu_dereference_protected(p->params, 1); - kfree_rcu(params, rcu); + if (params) + kfree_rcu(params, rcu); } static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
when the following command # tc action add action csum udp continue index 100 is run for the first time, and tcf_csum_init() fails allocating struct tcf_csum, tcf_csum_cleanup() calls kfree_rcu(NULL,...). This causes the following error: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: __call_rcu+0x23/0x2b0 PGD 80000000740b4067 P4D 80000000740b4067 PUD 32e7f067 PMD 0 Oops: 0002 [#1] SMP PTI Modules linked in: act_csum(E) act_vlan ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 mbcache jbd2 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_codec_generic pcbc snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer aesni_intel crypto_simd glue_helper cryptd snd joydev pcspkr virtio_balloon i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm virtio_blk drm virtio_net virtio_console ata_piix crc32c_intel libata virtio_pci serio_raw i2c_core virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_vlan] CPU: 2 PID: 5763 Comm: tc Tainted: G E 4.16.0-rc4.act_vlan.orig+ #403 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:__call_rcu+0x23/0x2b0 RSP: 0018:ffffb275803e77c0 EFLAGS: 00010246 RAX: ffffffffc057b080 RBX: ffff9674bc6f5240 RCX: 00000000ffffffff RDX: ffffffff928a5f00 RSI: 0000000000000008 RDI: 0000000000000008 RBP: 0000000000000008 R08: 0000000000000001 R09: 0000000000000044 R10: 0000000000000220 R11: ffff9674b9ab4821 R12: 0000000000000000 R13: ffffffff928a5f00 R14: 0000000000000000 R15: 0000000000000001 FS: 00007fa6368d8740(0000) GS:ffff9674bfd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000073dec001 CR4: 00000000001606e0 Call Trace: __tcf_idr_release+0x79/0xf0 tcf_csum_init+0xfb/0x180 [act_csum] tcf_action_init_1+0x2cc/0x430 tcf_action_init+0xd3/0x1b0 tc_ctl_action+0x18b/0x240 rtnetlink_rcv_msg+0x29c/0x310 ? _cond_resched+0x15/0x30 ? __kmalloc_node_track_caller+0x1b9/0x270 ? rtnl_calcit.isra.28+0x100/0x100 netlink_rcv_skb+0xd2/0x110 netlink_unicast+0x17c/0x230 netlink_sendmsg+0x2cd/0x3c0 sock_sendmsg+0x30/0x40 ___sys_sendmsg+0x27a/0x290 ? filemap_map_pages+0x34a/0x3a0 ? __handle_mm_fault+0xbfd/0xe20 __sys_sendmsg+0x51/0x90 do_syscall_64+0x6e/0x1a0 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x7fa635ce9ba0 RSP: 002b:00007ffc185b0fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ffc185b10f0 RCX: 00007fa635ce9ba0 RDX: 0000000000000000 RSI: 00007ffc185b1040 RDI: 0000000000000003 RBP: 000000005aaa85e0 R08: 0000000000000002 R09: 0000000000000000 R10: 00007ffc185b0a20 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc185b1104 R14: 0000000000000001 R15: 0000000000669f60 Code: 5d e9 42 da ff ff 66 90 0f 1f 44 00 00 41 57 41 56 41 55 49 89 d5 41 54 55 48 89 fd 53 48 83 ec 08 40 f6 c7 07 0f 85 19 02 00 00 <48> 89 75 08 48 c7 45 00 00 00 00 00 9c 58 0f 1f 44 00 00 49 89 RIP: __call_rcu+0x23/0x2b0 RSP: ffffb275803e77c0 CR2: 0000000000000010 fix this in tcf_csum_cleanup(), ensuring that kfree_rcu(param, ...) is called only when param is not NULL. Fixes: 9c5f69bbd75a ("net/sched: act_csum: don't use spinlock in the fast path") Signed-off-by: Davide Caratti <dcaratti@redhat.com> --- net/sched/act_csum.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)