diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-06-11 23:22:04 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-06-11 16:29:54 -0700 |
| commit | f6fadff33e8b09373eedf99822b89d9dd84545b8 (patch) | |
| tree | 6427ae4afbf4fb98be39eb4f0a2d565902d119d4 /net/tls/tls_main.c | |
| parent | a08ce73ba0a89be9f1418cba45fe94b39f9b73af (diff) | |
| download | linux-f6fadff33e8b09373eedf99822b89d9dd84545b8.tar.bz2 | |
tls: fix NULL pointer dereference on poll
While hacking on kTLS, I ran into the following panic from an
unprivileged netserver / netperf TCP session:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 800000037f378067 P4D 800000037f378067 PUD 3c0e61067 PMD 0
Oops: 0010 [#1] SMP KASAN PTI
CPU: 1 PID: 2289 Comm: netserver Not tainted 4.17.0+ #139
Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET47W (1.21 ) 11/28/2016
RIP: 0010: (null)
Code: Bad RIP value.
RSP: 0018:ffff88036abcf740 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88036f5f6800 RCX: 1ffff1006debed26
RDX: ffff88036abcf920 RSI: ffff8803cb1a4f00 RDI: ffff8803c258c280
RBP: ffff8803c258c280 R08: ffff8803c258c280 R09: ffffed006f559d48
R10: ffff88037aacea43 R11: ffffed006f559d49 R12: ffff8803c258c280
R13: ffff8803cb1a4f20 R14: 00000000000000db R15: ffffffffc168a350
FS: 00007f7e631f4700(0000) GS:ffff8803d1c80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000003ccf64005 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? tls_sw_poll+0xa4/0x160 [tls]
? sock_poll+0x20a/0x680
? do_select+0x77b/0x11a0
? poll_schedule_timeout.constprop.12+0x130/0x130
? pick_link+0xb00/0xb00
? read_word_at_a_time+0x13/0x20
? vfs_poll+0x270/0x270
? deref_stack_reg+0xad/0xe0
? __read_once_size_nocheck.constprop.6+0x10/0x10
[...]
Debugging further, it turns out that calling into ctx->sk_poll() is
invalid since sk_poll itself is NULL which was saved from the original
TCP socket in order for tls_sw_poll() to invoke it.
Looks like the recent conversion from poll to poll_mask callback started
in 152524231023 ("net: add support for ->poll_mask in proto_ops") missed
to eventually convert kTLS, too: TCP's ->poll was converted over to the
->poll_mask in commit 2c7d3dacebd4 ("net/tcp: convert to ->poll_mask")
and therefore kTLS wrongly saved the ->poll old one which is now NULL.
Convert kTLS over to use ->poll_mask instead. Also instead of POLLIN |
POLLRDNORM use the proper EPOLLIN | EPOLLRDNORM bits as the case in
tcp_poll_mask() as well that is mangled here.
Fixes: 2c7d3dacebd4 ("net/tcp: convert to ->poll_mask")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Watson <davejwatson@fb.com>
Tested-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tls/tls_main.c')
| -rw-r--r-- | net/tls/tls_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 301f22430469..a127d61e8af9 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -712,7 +712,7 @@ static int __init tls_register(void) build_protos(tls_prots[TLSV4], &tcp_prot); tls_sw_proto_ops = inet_stream_ops; - tls_sw_proto_ops.poll = tls_sw_poll; + tls_sw_proto_ops.poll_mask = tls_sw_poll_mask; tls_sw_proto_ops.splice_read = tls_sw_splice_read; #ifdef CONFIG_TLS_DEVICE |