net: sched: ife: fix potential use-after-free
[ Upstream commit 19391a2c ] ife_decode() calls pskb_may_pull() two times, we need to reload ifehdr after the second one, or risk use-after-free as reported by syzbot: BUG: KASAN: slab-use-after-free in __ife_tlv_meta_valid net/ife/ife.c:108 [inline] BUG: KASAN: slab-use-after-free in ife_tlv_meta_decode+0x1d1/0x210 net/ife/ife.c:131 Read of size 2 at addr ffff88802d7300a4 by task syz-executor.5/22323 CPU: 0 PID: 22323 Comm: syz-executor.5 Not tainted 6.7.0-rc3-syzkaller-00804-g074ac38d5b95 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 __ife_tlv_meta_valid net/ife/ife.c:108 [inline] ife_tlv_meta_decode+0x1d1/0x210 net/ife/ife.c:131 tcf_ife_decode net/sched/act_ife.c:739 [inline] tcf_ife_act+0x4e3/0x1cd0 net/sched/act_ife.c:879 tc_act include/net/tc_wrapper.h:221 [inline] tcf_action_exec+0x1ac/0x620 net/sched/act_api.c:1079 tcf_exts_exec include/net/pkt_cls.h:344 [inline] mall_classify+0x201/0x310 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:227 [inline] __tcf_classify net/sched/cls_api.c:1703 [inline] tcf_classify+0x82f/0x1260 net/sched/cls_api.c:1800 hfsc_classify net/sched/sch_hfsc.c:1147 [inline] hfsc_enqueue+0x315/0x1060 net/sched/sch_hfsc.c:1546 dev_qdisc_enqueue+0x3f/0x230 net/core/dev.c:3739 __dev_xmit_skb net/core/dev.c:3828 [inline] __dev_queue_xmit+0x1de1/0x3d30 net/core/dev.c:4311 dev_queue_xmit include/linux/netdevice.h:3165 [inline] packet_xmit+0x237/0x350 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3081 [inline] packet_sendmsg+0x24aa/0x5200 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 __sys_sendto+0x255/0x340 net/socket.c:2190 __do_sys_sendto net/socket.c:2202 [inline] __se_sys_sendto net/socket.c:2198 [inline] __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2198 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fe9acc7cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe9ada450c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fe9acd9bf80 RCX: 00007fe9acc7cae9 RDX: 000000000000fce0 RSI: 00000000200002c0 RDI: 0000000000000003 RBP: 00007fe9accc847a R08: 0000000020000140 R09: 0000000000000014 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fe9acd9bf80 R15: 00007ffd5427ae78 </TASK> Allocated by task 22323: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node_track_caller+0x5a/0x90 mm/slab_common.c:1027 kmalloc_reserve+0xef/0x260 net/core/skbuff.c:582 __alloc_skb+0x12b/0x330 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1298 [inline] alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6331 sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2780 packet_alloc_skb net/packet/af_packet.c:2930 [inline] packet_snd net/packet/af_packet.c:3024 [inline] packet_sendmsg+0x1e2a/0x5200 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 __sys_sendto+0x255/0x340 net/socket.c:2190 __do_sys_sendto net/socket.c:2202 [inline] __se_sys_sendto net/socket.c:2198 [inline] __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2198 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Freed by task 22323: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xc0/0x180 mm/slub.c:3822 skb_kfree_head net/core/skbuff.c:950 [inline] skb_free_head+0x110/0x1b0 net/core/skbuff.c:962 pskb_expand_head+0x3c5/0x1170 net/core/skbuff.c:2130 __pskb_pull_tail+0xe1/0x1830 net/core/skbuff.c:2655 pskb_may_pull_reason include/linux/skbuff.h:2685 [inline] pskb_may_pull include/linux/skbuff.h:2693 [inline] ife_decode+0x394/0x4f0 net/ife/ife.c:82 tcf_ife_decode net/sched/act_ife.c:727 [inline] tcf_ife_act+0x43b/0x1cd0 net/sched/act_ife.c:879 tc_act include/net/tc_wrapper.h:221 [inline] tcf_action_exec+0x1ac/0x620 net/sched/act_api.c:1079 tcf_exts_exec include/net/pkt_cls.h:344 [inline] mall_classify+0x201/0x310 net/sched/cls_matchall.c:42 tc_classify include/net/tc_wrapper.h:227 [inline] __tcf_classify net/sched/cls_api.c:1703 [inline] tcf_classify+0x82f/0x1260 net/sched/cls_api.c:1800 hfsc_classify net/sched/sch_hfsc.c:1147 [inline] hfsc_enqueue+0x315/0x1060 net/sched/sch_hfsc.c:1546 dev_qdisc_enqueue+0x3f/0x230 net/core/dev.c:3739 __dev_xmit_skb net/core/dev.c:3828 [inline] __dev_queue_xmit+0x1de1/0x3d30 net/core/dev.c:4311 dev_queue_xmit include/linux/netdevice.h:3165 [inline] packet_xmit+0x237/0x350 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3081 [inline] packet_sendmsg+0x24aa/0x5200 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 __sys_sendto+0x255/0x340 net/socket.c:2190 __do_sys_sendto net/socket.c:2202 [inline] __se_sys_sendto net/socket.c:2198 [inline] __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2198 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff88802d730000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 164 bytes inside of freed 8192-byte region [ffff88802d730000, ffff88802d732000) The buggy address belongs to the physical page: page:ffffea0000b5cc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2d730 head:ffffea0000b5cc00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888013042280 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 22323, tgid 22320 (syz-executor.5), ts 950317230369, free_ts 950233467461 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1544 prep_new_page mm/page_alloc.c:1551 [inline] get_page_from_freelist+0xa28/0x3730 mm/page_alloc.c:3319 __alloc_pages+0x22e/0x2420 mm/page_alloc.c:4575 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab mm/slub.c:2017 [inline] new_slab+0x283/0x3c0 mm/slub.c:2070 ___slab_alloc+0x979/0x1500 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x310 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0x4a/0x90 mm/slab_common.c:1027 kmalloc_reserve+0xef/0x260 net/core/skbuff.c:582 __alloc_skb+0x12b/0x330 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1298 [inline] alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6331 sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2780 packet_alloc_skb net/packet/af_packet.c:2930 [inline] packet_snd net/packet/af_packet.c:3024 [inline] packet_sendmsg+0x1e2a/0x5200 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 __sys_sendto+0x255/0x340 net/socket.c:2190 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1144 [inline] free_unref_page_prepare+0x53c/0xb80 mm/page_alloc.c:2354 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2494 __unfreeze_partials+0x226/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc_lru+0x219/0x6f0 mm/slub.c:3509 alloc_inode_sb include/linux/fs.h:2937 [inline] ext4_alloc_inode+0x28/0x650 fs/ext4/super.c:1408 alloc_inode+0x5d/0x220 fs/inode.c:261 new_inode_pseudo fs/inode.c:1006 [inline] new_inode+0x22/0x260 fs/inode.c:1032 __ext4_new_inode+0x333/0x5200 fs/ext4/ialloc.c:958 ext4_symlink+0x5d7/0xa20 fs/ext4/namei.c:3398 vfs_symlink fs/namei.c:4464 [inline] vfs_symlink+0x3e5/0x620 fs/namei.c:4448 do_symlinkat+0x25f/0x310 fs/namei.c:4490 __do_sys_symlinkat fs/namei.c:4506 [inline] __se_sys_symlinkat fs/namei.c:4503 [inline] __x64_sys_symlinkat+0x97/0xc0 fs/namei.c:4503 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 Fixes: d57493d6 ("net: sched: ife: check on metadata length") Reported-by:syzbot <syzkaller@googlegroups.com> Signed-off-by:
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