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| author |   Takeshi Misawa <jeliantsurux@gmail.com> | 2019-09-22 16:45:31 +0900 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-09-25 13:45:03 +0200 |
| commit | 4c247de564f1ff614d11b3bb5313fb70d7b9598b (patch) | |
| tree | c850ab77c6889f197fa67f26bc032ae9265e7028 | |
| parent | Merge branch 'ibmvnic-serialization-fixes' (diff) | |
| download | linux-dev-4c247de564f1ff614d11b3bb5313fb70d7b9598b.tar.xz linux-dev-4c247de564f1ff614d11b3bb5313fb70d7b9598b.zip | |
ppp: Fix memory leak in ppp_write
When ppp is closing, __ppp_xmit_process() failed to enqueue skb
and skb allocated in ppp_write() is leaked.
syzbot reported :
BUG: memory leak
unreferenced object 0xffff88812a17bc00 (size 224):
comm "syz-executor673", pid 6952, jiffies 4294942888 (age 13.040s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000d110fff9>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
[<00000000d110fff9>] slab_post_alloc_hook mm/slab.h:522 [inline]
[<00000000d110fff9>] slab_alloc_node mm/slab.c:3262 [inline]
[<00000000d110fff9>] kmem_cache_alloc_node+0x163/0x2f0 mm/slab.c:3574
[<000000002d616113>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:197
[<000000000167fc45>] alloc_skb include/linux/skbuff.h:1055 [inline]
[<000000000167fc45>] ppp_write+0x48/0x120 drivers/net/ppp/ppp_generic.c:502
[<000000009ab42c0b>] __vfs_write+0x43/0xa0 fs/read_write.c:494
[<00000000086b2e22>] vfs_write fs/read_write.c:558 [inline]
[<00000000086b2e22>] vfs_write+0xee/0x210 fs/read_write.c:542
[<00000000a2b70ef9>] ksys_write+0x7c/0x130 fs/read_write.c:611
[<00000000ce5e0fdd>] __do_sys_write fs/read_write.c:623 [inline]
[<00000000ce5e0fdd>] __se_sys_write fs/read_write.c:620 [inline]
[<00000000ce5e0fdd>] __x64_sys_write+0x1e/0x30 fs/read_write.c:620
[<00000000d9d7b370>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:296
[<0000000006e6d506>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by freeing skb, if ppp is closing.
Fixes: 6d066734e9f0 ("ppp: avoid loop in xmit recursion detection code")
Reported-and-tested-by: syzbot+d9c8bf24e56416d7ce2c@syzkaller.appspotmail.com
Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Tested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ppp/ppp_generic.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index a30e41a56085..9a1b006904a7 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -1415,6 +1415,8 @@ static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) netif_wake_queue(ppp->dev); else netif_stop_queue(ppp->dev); + } else { + kfree_skb(skb); } ppp_xmit_unlock(ppp); } |