https://github.com/torvalds/linux
Revision c9a368f1c0fbe2e3a21ebf231caeae58b18b2681 authored by Martin KaFai Lau on 09 July 2020, 06:11:10 UTC, committed by Daniel Borkmann on 09 July 2020, 20:03:31 UTC
bpf_sk_reuseport_detach is currently called when sk->sk_user_data is not NULL. It is incorrect because sk->sk_user_data may not be managed by the bpf's reuseport_array. It has been reported in [1] that, the bpf_sk_reuseport_detach() which is called from udp_lib_unhash() has corrupted the sk_user_data managed by l2tp. This patch solves it by using another bit (defined as SK_USER_DATA_BPF) of the sk_user_data pointer value. It marks that a sk_user_data is managed/owned by BPF. The patch depends on a PTRMASK introduced in commit f1ff5ce2cd5e ("net, sk_msg: Clear sk_user_data pointer on clone if tagged"). [ Note: sk->sk_user_data is used by bpf's reuseport_array only when a sk is added to the bpf's reuseport_array. i.e. doing setsockopt(SO_REUSEPORT) and having "sk->sk_reuseport == 1" alone will not stop sk->sk_user_data being used by other means. ] [1]: https://lore.kernel.org/netdev/20200706121259.GA20199@katalix.com/ Fixes: 5dc4c4b7d4e8 ("bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY") Reported-by: James Chapman <jchapman@katalix.com> Reported-by: syzbot+9f092552ba9a5efca5df@syzkaller.appspotmail.com Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: James Chapman <jchapman@katalix.com> Acked-by: James Chapman <jchapman@katalix.com> Link: https://lore.kernel.org/bpf/20200709061110.4019316-1-kafai@fb.com
1 parent f3dda7a
Tip revision: c9a368f1c0fbe2e3a21ebf231caeae58b18b2681 authored by Martin KaFai Lau on 09 July 2020, 06:11:10 UTC
bpf: net: Avoid incorrect bpf_sk_reuseport_detach call
bpf: net: Avoid incorrect bpf_sk_reuseport_detach call
Tip revision: c9a368f
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arch | ||
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certs | ||
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fs | ||
include | ||
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ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
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usr | ||
virt | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 71 bytes |
.gitattributes | -rw-r--r-- | 62 bytes |
.gitignore | -rw-r--r-- | 1.8 KB |
.mailmap | -rw-r--r-- | 15.4 KB |
COPYING | -rw-r--r-- | 496 bytes |
CREDITS | -rw-r--r-- | 97.4 KB |
Kbuild | -rw-r--r-- | 1.3 KB |
Kconfig | -rw-r--r-- | 555 bytes |
MAINTAINERS | -rw-r--r-- | 547.8 KB |
Makefile | -rw-r--r-- | 60.4 KB |
README | -rw-r--r-- | 727 bytes |
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