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author | Daniel Borkmann <daniel@iogearbox.net> | 2018-06-11 23:22:04 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-06-12 01:29:54 +0200 |
commit | f6fadff33e8b09373eedf99822b89d9dd84545b8 (patch) | |
tree | 6427ae4afbf4fb98be39eb4f0a2d565902d119d4 /include | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf (diff) | |
download | linux-f6fadff33e8b09373eedf99822b89d9dd84545b8.tar.xz linux-f6fadff33e8b09373eedf99822b89d9dd84545b8.zip |
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 'include')
-rw-r--r-- | include/net/tls.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/include/net/tls.h b/include/net/tls.h index 70c273777fe9..7f84ea3e217c 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -109,8 +109,7 @@ struct tls_sw_context_rx { struct strparser strp; void (*saved_data_ready)(struct sock *sk); - unsigned int (*sk_poll)(struct file *file, struct socket *sock, - struct poll_table_struct *wait); + __poll_t (*sk_poll_mask)(struct socket *sock, __poll_t events); struct sk_buff *recv_pkt; u8 control; bool decrypted; @@ -225,8 +224,7 @@ void tls_sw_free_resources_tx(struct sock *sk); void tls_sw_free_resources_rx(struct sock *sk); int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, int flags, int *addr_len); -unsigned int tls_sw_poll(struct file *file, struct socket *sock, - struct poll_table_struct *wait); +__poll_t tls_sw_poll_mask(struct socket *sock, __poll_t events); ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags); |