memory leak in pppoe_sendmsg

From: syzbot
Date: Thu May 30 2019 - 23:51:46 EST

Hello,

syzbot found the following crash on:

HEAD commit: bec7550c Merge tag 'docs-5.2-fixes2' of git://git.lwn.net/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1280ecbaa00000
kernel config: https://syzkaller.appspot.com/x/.config?x=64479170dcaf0e11
dashboard link: https://syzkaller.appspot.com/bug?extid=6bdfd184eac7709e5cc9
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17112572a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6bdfd184eac7709e5cc9@xxxxxxxxxxxxxxxxxxxxxxxxx

2019/05/30 11:35:26 executed programs: 9
2019/05/30 11:35:32 executed programs: 11
2019/05/30 11:35:38 executed programs: 13
2019/05/30 11:35:44 executed programs: 15
2019/05/30 11:35:50 executed programs: 17
BUG: memory leak
unreferenced object 0xffff888124199500 (size 224):
comm "syz-executor.0", pid 7122, jiffies 4295041954 (age 13.860s)
hex dump (first 32 bytes):
00 96 19 24 81 88 ff ff d0 20 0e 2a 81 88 ff ff ...$..... .*....
00 00 00 00 00 00 00 00 00 20 0e 2a 81 88 ff ff ......... .*....
backtrace:
[<00000000688f689a>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<00000000688f689a>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<00000000688f689a>] slab_alloc_node mm/slab.c:3269 [inline]
[<00000000688f689a>] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
[<00000000e781c880>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
[<000000004ce3be0b>] alloc_skb include/linux/skbuff.h:1058 [inline]
[<000000004ce3be0b>] sock_wmalloc+0x4f/0x80 net/core/sock.c:2077
[<000000008110994c>] pppoe_sendmsg+0xd0/0x250 drivers/net/ppp/pppoe.c:871
[<00000000c1e51321>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000c1e51321>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<000000008012ebfd>] ___sys_sendmsg+0x194/0x3c0 net/socket.c:2292
[<0000000087b8ef6f>] __sys_sendmmsg+0xf4/0x270 net/socket.c:2387
[<000000002b3700b1>] __do_sys_sendmmsg net/socket.c:2416 [inline]
[<000000002b3700b1>] __se_sys_sendmmsg net/socket.c:2413 [inline]
[<000000002b3700b1>] __x64_sys_sendmmsg+0x28/0x30 net/socket.c:2413
[<0000000028e31f9f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
[<000000004279bc05>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff888115706600 (size 512):
comm "syz-executor.0", pid 7122, jiffies 4295041954 (age 13.860s)
hex dump (first 32 bytes):
23 32 aa aa aa aa aa 0a aa aa aa aa aa 0a 88 64 #2.............d
11 00 04 00 00 00 70 72 6f 66 69 6c 65 3d 30 20 ......profile=0
backtrace:
[<00000000c07b4ae3>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<00000000c07b4ae3>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<00000000c07b4ae3>] slab_alloc_node mm/slab.c:3269 [inline]
[<00000000c07b4ae3>] kmem_cache_alloc_node_trace+0x15b/0x2a0 mm/slab.c:3597
[<00000000e84718bb>] __do_kmalloc_node mm/slab.c:3619 [inline]
[<00000000e84718bb>] __kmalloc_node_track_caller+0x38/0x50 mm/slab.c:3634
[<000000008692fea3>] __kmalloc_reserve.isra.0+0x40/0xb0 net/core/skbuff.c:142
[<00000000da312aad>] __alloc_skb+0xa0/0x210 net/core/skbuff.c:210
[<000000004ce3be0b>] alloc_skb include/linux/skbuff.h:1058 [inline]
[<000000004ce3be0b>] sock_wmalloc+0x4f/0x80 net/core/sock.c:2077
[<000000008110994c>] pppoe_sendmsg+0xd0/0x250 drivers/net/ppp/pppoe.c:871
[<00000000c1e51321>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000c1e51321>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<000000008012ebfd>] ___sys_sendmsg+0x194/0x3c0 net/socket.c:2292
[<0000000087b8ef6f>] __sys_sendmmsg+0xf4/0x270 net/socket.c:2387
[<000000002b3700b1>] __do_sys_sendmmsg net/socket.c:2416 [inline]
[<000000002b3700b1>] __se_sys_sendmmsg net/socket.c:2413 [inline]
[<000000002b3700b1>] __x64_sys_sendmmsg+0x28/0x30 net/socket.c:2413
[<0000000028e31f9f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
[<000000004279bc05>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff888124199600 (size 224):
comm "syz-executor.0", pid 7122, jiffies 4295041954 (age 13.860s)
hex dump (first 32 bytes):
00 97 19 24 81 88 ff ff 00 95 19 24 81 88 ff ff ...$.......$....
00 00 00 00 00 00 00 00 00 20 0e 2a 81 88 ff ff ......... .*....
backtrace:
[<00000000688f689a>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<00000000688f689a>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<00000000688f689a>] slab_alloc_node mm/slab.c:3269 [inline]
[<00000000688f689a>] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
[<00000000e781c880>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
[<000000004ce3be0b>] alloc_skb include/linux/skbuff.h:1058 [inline]
[<000000004ce3be0b>] sock_wmalloc+0x4f/0x80 net/core/sock.c:2077
[<000000008110994c>] pppoe_sendmsg+0xd0/0x250 drivers/net/ppp/pppoe.c:871
[<00000000c1e51321>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000c1e51321>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<000000008012ebfd>] ___sys_sendmsg+0x194/0x3c0 net/socket.c:2292
[<0000000087b8ef6f>] __sys_sendmmsg+0xf4/0x270 net/socket.c:2387
[<000000002b3700b1>] __do_sys_sendmmsg net/socket.c:2416 [inline]
[<000000002b3700b1>] __se_sys_sendmmsg net/socket.c:2413 [inline]
[<000000002b3700b1>] __x64_sys_sendmmsg+0x28/0x30 net/socket.c:2413
[<0000000028e31f9f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
[<000000004279bc05>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811a0b2600 (size 512):
comm "syz-executor.0", pid 7122, jiffies 4295041954 (age 13.860s)
hex dump (first 32 bytes):
00 00 aa aa aa aa aa 0a aa aa aa aa aa 0a 88 64 ...............d
11 00 04 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000c07b4ae3>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<00000000c07b4ae3>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<00000000c07b4ae3>] slab_alloc_node mm/slab.c:3269 [inline]
[<00000000c07b4ae3>] kmem_cache_alloc_node_trace+0x15b/0x2a0 mm/slab.c:3597
[<00000000e84718bb>] __do_kmalloc_node mm/slab.c:3619 [inline]
[<00000000e84718bb>] __kmalloc_node_track_caller+0x38/0x50 mm/slab.c:3634
[<000000008692fea3>] __kmalloc_reserve.isra.0+0x40/0xb0 net/core/skbuff.c:142
[<00000000da312aad>] __alloc_skb+0xa0/0x210 net/core/skbuff.c:210
[<000000004ce3be0b>] alloc_skb include/linux/skbuff.h:1058 [inline]
[<000000004ce3be0b>] sock_wmalloc+0x4f/0x80 net/core/sock.c:2077
[<000000008110994c>] pppoe_sendmsg+0xd0/0x250 drivers/net/ppp/pppoe.c:871
[<00000000c1e51321>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<00000000c1e51321>] sock_sendmsg+0x54/0x70 net/socket.c:671
[<000000008012ebfd>] ___sys_sendmsg+0x194/0x3c0 net/socket.c:2292
[<0000000087b8ef6f>] __sys_sendmmsg+0xf4/0x270 net/socket.c:2387
[<000000002b3700b1>] __do_sys_sendmmsg net/socket.c:2416 [inline]
[<000000002b3700b1>] __se_sys_sendmmsg net/socket.c:2413 [inline]
[<000000002b3700b1>] __x64_sys_sendmmsg+0x28/0x30 net/socket.c:2413
[<0000000028e31f9f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
[<000000004279bc05>] entry_SYSCALL_64_after_hwframe+0x44/0xa9



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