linux-stable.git/net/core/skmsg.c, branch v5.4.3 Linux kernel stable tree net: skmsg: fix TLS 1.3 crash with full sk_msg 2019-12-04T21:31:01+00:00 Jakub Kicinski jakub.kicinski@netronome.com 2019-11-27T20:16:41+00:00 3cef7ef9c42562212574c32b98fbb1617a2ff515 [ Upstream commit 031097d9e079e40dce401031d1012e83d80eaf01 ] TLS 1.3 started using the entry at the end of the SG array for chaining-in the single byte content type entry. This mostly works: [ E E E E E E . . ] ^ ^ start end E < content type / [ E E E E E E C . ] ^ ^ start end (Where E denotes a populated SG entry; C denotes a chaining entry.) If the array is full, however, the end will point to the start: [ E E E E E E E E ] ^ start end And we end up overwriting the start: E < content type / [ C E E E E E E E ] ^ start end The sg array is supposed to be a circular buffer with start and end markers pointing anywhere. In case where start > end (i.e. the circular buffer has "wrapped") there is an extra entry reserved at the end to chain the two halves together. [ E E E E E E . . l ] (Where l is the reserved entry for "looping" back to front. As suggested by John, let's reserve another entry for chaining SG entries after the main circular buffer. Note that this entry has to be pointed to by the end entry so its position is not fixed. Examples of full messages: [ E E E E E E E E . l ] ^ ^ start end <---------------. [ E E . E E E E E E l ] ^ ^ end start Now the end will always point to an unused entry, so TLS 1.3 can always use it. Fixes: 130b392c6cd6 ("net: tls: Add tls 1.3 support") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 031097d9e079e40dce401031d1012e83d80eaf01 ]

TLS 1.3 started using the entry at the end of the SG array
for chaining-in the single byte content type entry. This mostly
works:

[ E E E E E E . . ]
  ^           ^
   start       end

                 E < content type
               /
[ E E E E E E C . ]
  ^           ^
   start       end

(Where E denotes a populated SG entry; C denotes a chaining entry.)

If the array is full, however, the end will point to the start:

[ E E E E E E E E ]
  ^
   start
   end

And we end up overwriting the start:

    E < content type
   /
[ C E E E E E E E ]
  ^
   start
   end

The sg array is supposed to be a circular buffer with start and
end markers pointing anywhere. In case where start > end
(i.e. the circular buffer has "wrapped") there is an extra entry
reserved at the end to chain the two halves together.

[ E E E E E E . . l ]

(Where l is the reserved entry for "looping" back to front.

As suggested by John, let's reserve another entry for chaining
SG entries after the main circular buffer. Note that this entry
has to be pointed to by the end entry so its position is not fixed.

Examples of full messages:

[ E E E E E E E E . l ]
  ^               ^
   start           end

   <---------------.
[ E E . E E E E E E l ]
      ^ ^
   end   start

Now the end will always point to an unused entry, so TLS 1.3
can always use it.

Fixes: 130b392c6cd6 ("net: tls: Add tls 1.3 support")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/tls: fix sk_msg trim on fallback to copy mode 2019-11-06T02:07:47+00:00 Jakub Kicinski jakub.kicinski@netronome.com 2019-11-04T23:36:57+00:00 683916f6a84023407761d843048f1aea486b2612 sk_msg_trim() tries to only update curr pointer if it falls into the trimmed region. The logic, however, does not take into the account pointer wrapping that sk_msg_iter_var_prev() does nor (as John points out) the fact that msg->sg is a ring buffer. This means that when the message was trimmed completely, the new curr pointer would have the value of MAX_MSG_FRAGS - 1, which is neither smaller than any other value, nor would it actually be correct. Special case the trimming to 0 length a little bit and rework the comparison between curr and end to take into account wrapping. This bug caused the TLS code to not copy all of the message, if zero copy filled in fewer sg entries than memcopy would need. Big thanks to Alexander Potapenko for the non-KMSAN reproducer. v2: - take into account that msg->sg is a ring buffer (John). Link: https://lore.kernel.org/netdev/20191030160542.30295-1-jakub.kicinski@netronome.com/ (v1) Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface") Reported-by: syzbot+f8495bff23a879a6d0bd@syzkaller.appspotmail.com Reported-by: syzbot+6f50c99e8f6194bf363f@syzkaller.appspotmail.com Co-developed-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
sk_msg_trim() tries to only update curr pointer if it falls into
the trimmed region. The logic, however, does not take into the
account pointer wrapping that sk_msg_iter_var_prev() does nor
(as John points out) the fact that msg->sg is a ring buffer.

This means that when the message was trimmed completely, the new
curr pointer would have the value of MAX_MSG_FRAGS - 1, which is
neither smaller than any other value, nor would it actually be
correct.

Special case the trimming to 0 length a little bit and rework
the comparison between curr and end to take into account wrapping.

This bug caused the TLS code to not copy all of the message, if
zero copy filled in fewer sg entries than memcopy would need.

Big thanks to Alexander Potapenko for the non-KMSAN reproducer.

v2:
 - take into account that msg->sg is a ring buffer (John).

Link: https://lore.kernel.org/netdev/20191030160542.30295-1-jakub.kicinski@netronome.com/ (v1)

Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface")
Reported-by: syzbot+f8495bff23a879a6d0bd@syzkaller.appspotmail.com
Reported-by: syzbot+6f50c99e8f6194bf363f@syzkaller.appspotmail.com
Co-developed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/core/skmsg: Delete an unnecessary check before the function call “consume_skb” 2019-08-24T23:24:53+00:00 Markus Elfring elfring@users.sourceforge.net 2019-08-22T16:00:40+00:00 dd016aca28f67603f32c4e666805db519df2120a The consume_skb() function performs also input parameter validation. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The consume_skb() function performs also input parameter validation.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf: sockmap/tls, close can race with map free 2019-07-22T14:04:17+00:00 John Fastabend john.fastabend@gmail.com 2019-07-19T17:29:22+00:00 95fa145479fbc0a0c1fd3274ceb42ec03c042a4a When a map free is called and in parallel a socket is closed we have two paths that can potentially reset the socket prot ops, the bpf close() path and the map free path. This creates a problem with which prot ops should be used from the socket closed side. If the map_free side completes first then we want to call the original lowest level ops. However, if the tls path runs first we want to call the sockmap ops. Additionally there was no locking around prot updates in TLS code paths so the prot ops could be changed multiple times once from TLS path and again from sockmap side potentially leaving ops pointed at either TLS or sockmap when psock and/or tls context have already been destroyed. To fix this race first only update ops inside callback lock so that TLS, sockmap and lowest level all agree on prot state. Second and a ULP callback update() so that lower layers can inform the upper layer when they are being removed allowing the upper layer to reset prot ops. This gets us close to allowing sockmap and tls to be stacked in arbitrary order but will save that patch for *next trees. v4: - make sure we don't free things for device; - remove the checks which swap the callbacks back only if TLS is at the top. Reported-by: syzbot+06537213db7ba2745c4a@syzkaller.appspotmail.com Fixes: 02c558b2d5d6 ("bpf: sockmap, support for msg_peek in sk_msg with redirect ingress") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
When a map free is called and in parallel a socket is closed we
have two paths that can potentially reset the socket prot ops, the
bpf close() path and the map free path. This creates a problem
with which prot ops should be used from the socket closed side.

If the map_free side completes first then we want to call the
original lowest level ops. However, if the tls path runs first
we want to call the sockmap ops. Additionally there was no locking
around prot updates in TLS code paths so the prot ops could
be changed multiple times once from TLS path and again from sockmap
side potentially leaving ops pointed at either TLS or sockmap
when psock and/or tls context have already been destroyed.

To fix this race first only update ops inside callback lock
so that TLS, sockmap and lowest level all agree on prot state.
Second and a ULP callback update() so that lower layers can
inform the upper layer when they are being removed allowing the
upper layer to reset prot ops.

This gets us close to allowing sockmap and tls to be stacked
in arbitrary order but will save that patch for *next trees.

v4:
 - make sure we don't free things for device;
 - remove the checks which swap the callbacks back
   only if TLS is at the top.

Reported-by: syzbot+06537213db7ba2745c4a@syzkaller.appspotmail.com
Fixes: 02c558b2d5d6 ("bpf: sockmap, support for msg_peek in sk_msg with redirect ingress")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
bpf: sockmap fix msg->sg.size account on ingress skb 2019-05-13T23:31:43+00:00 John Fastabend john.fastabend@gmail.com 2019-05-13T14:19:55+00:00 cabede8b4f2b746232aa25730a0b752de1cb82ca When converting a skb to msg->sg we forget to set the size after the latest ktls/tls code conversion. This patch can be reached by doing a redir into ingress path from BPF skb sock recv hook. Then trying to read the size fails. Fix this by setting the size. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
When converting a skb to msg->sg we forget to set the size after the
latest ktls/tls code conversion. This patch can be reached by doing
a redir into ingress path from BPF skb sock recv hook. Then trying to
read the size fails.

Fix this by setting the size.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
bpf: sockmap, only stop/flush strp if it was enabled at some point 2019-05-13T23:31:31+00:00 John Fastabend john.fastabend@gmail.com 2019-05-13T14:19:19+00:00 014894360ec95abe868e94416b3dd6569f6e2c0c If we try to call strp_done on a parser that has never been initialized, because the sockmap user is only using TX side for example we get the following error. [ 883.422081] WARNING: CPU: 1 PID: 208 at kernel/workqueue.c:3030 __flush_work+0x1ca/0x1e0 ... [ 883.422095] Workqueue: events sk_psock_destroy_deferred [ 883.422097] RIP: 0010:__flush_work+0x1ca/0x1e0 This had been wrapped in a 'if (psock->parser.enabled)' logic which was broken because the strp_done() was never actually being called because we do a strp_stop() earlier in the tear down logic will set parser.enabled to false. This could result in a use after free if work was still in the queue and was resolved by the patch here, 1d79895aef18f ("sk_msg: Always cancel strp work before freeing the psock"). However, calling strp_stop(), done by the patch marked in the fixes tag, only is useful if we never initialized a strp parser program and never initialized the strp to start with. Because if we had initialized a stream parser strp_stop() would have been called by sk_psock_drop() earlier in the tear down process. By forcing the strp to stop we get past the WARNING in strp_done that checks the stopped flag but calling cancel_work_sync on work that has never been initialized is also wrong and generates the warning above. To fix check if the parser program exists. If the program exists then the strp work has been initialized and must be sync'd and cancelled before free'ing any structures. If no program exists we never initialized the stream parser in the first place so skip the sync/cancel logic implemented by strp_done. Finally, remove the strp_done its not needed and in the case where we are using the stream parser has already been called. Fixes: e8e3437762ad9 ("bpf: Stop the psock parser before canceling its work") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
If we try to call strp_done on a parser that has never been
initialized, because the sockmap user is only using TX side for
example we get the following error.

  [  883.422081] WARNING: CPU: 1 PID: 208 at kernel/workqueue.c:3030 __flush_work+0x1ca/0x1e0
  ...
  [  883.422095] Workqueue: events sk_psock_destroy_deferred
  [  883.422097] RIP: 0010:__flush_work+0x1ca/0x1e0

This had been wrapped in a 'if (psock->parser.enabled)' logic which
was broken because the strp_done() was never actually being called
because we do a strp_stop() earlier in the tear down logic will
set parser.enabled to false. This could result in a use after free
if work was still in the queue and was resolved by the patch here,
1d79895aef18f ("sk_msg: Always cancel strp work before freeing the
psock"). However, calling strp_stop(), done by the patch marked in
the fixes tag, only is useful if we never initialized a strp parser
program and never initialized the strp to start with. Because if
we had initialized a stream parser strp_stop() would have been called
by sk_psock_drop() earlier in the tear down process.  By forcing the
strp to stop we get past the WARNING in strp_done that checks
the stopped flag but calling cancel_work_sync on work that has never
been initialized is also wrong and generates the warning above.

To fix check if the parser program exists. If the program exists
then the strp work has been initialized and must be sync'd and
cancelled before free'ing any structures. If no program exists we
never initialized the stream parser in the first place so skip the
sync/cancel logic implemented by strp_done.

Finally, remove the strp_done its not needed and in the case where we
are using the stream parser has already been called.

Fixes: e8e3437762ad9 ("bpf: Stop the psock parser before canceling its work")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
bpf: Stop the psock parser before canceling its work 2019-03-07T14:16:20+00:00 Jakub Sitnicki jakub@cloudflare.com 2019-03-07T10:35:43+00:00 e8e3437762ad938880dd48a3c52d702e7cf3c124 We might have never enabled (started) the psock's parser, in which case it will not get stopped when destroying the psock. This leads to a warning when trying to cancel parser's work from psock's deferred destructor: [ 405.325769] WARNING: CPU: 1 PID: 3216 at net/strparser/strparser.c:526 strp_done+0x3c/0x40 [ 405.326712] Modules linked in: [last unloaded: test_bpf] [ 405.327359] CPU: 1 PID: 3216 Comm: kworker/1:164 Tainted: G W 5.0.0 #42 [ 405.328294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20180531_142017-buildhw-08.phx2.fedoraproject.org-1.fc28 04/01/2014 [ 405.329712] Workqueue: events sk_psock_destroy_deferred [ 405.330254] RIP: 0010:strp_done+0x3c/0x40 [ 405.330706] Code: 28 e8 b8 d5 6b ff 48 8d bb 80 00 00 00 e8 9c d5 6b ff 48 8b 7b 18 48 85 ff 74 0d e8 1e a5 e8 ff 48 c7 43 18 00 00 00 00 5b c3 <0f> 0b eb cf 66 66 66 66 90 55 89 f5 53 48 89 fb 48 83 c7 28 e8 0b [ 405.332862] RSP: 0018:ffffc900026bbe50 EFLAGS: 00010246 [ 405.333482] RAX: ffffffff819323e0 RBX: ffff88812cb83640 RCX: ffff88812cb829e8 [ 405.334228] RDX: 0000000000000001 RSI: ffff88812cb837e8 RDI: ffff88812cb83640 [ 405.335366] RBP: ffff88813fd22680 R08: 0000000000000000 R09: 000073746e657665 [ 405.336472] R10: 8080808080808080 R11: 0000000000000001 R12: ffff88812cb83600 [ 405.337760] R13: 0000000000000000 R14: ffff88811f401780 R15: ffff88812cb837e8 [ 405.338777] FS: 0000000000000000(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000 [ 405.339903] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 405.340821] CR2: 00007fb11489a6b8 CR3: 000000012d4d6000 CR4: 00000000000406e0 [ 405.341981] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 405.343131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 405.344415] Call Trace: [ 405.344821] sk_psock_destroy_deferred+0x23/0x1b0 [ 405.345585] process_one_work+0x1ae/0x3e0 [ 405.346110] worker_thread+0x3c/0x3b0 [ 405.346576] ? pwq_unbound_release_workfn+0xd0/0xd0 [ 405.347187] kthread+0x11d/0x140 [ 405.347601] ? __kthread_parkme+0x80/0x80 [ 405.348108] ret_from_fork+0x35/0x40 [ 405.348566] ---[ end trace a4a3af4026a327d4 ]--- Stop psock's parser just before canceling its work. Fixes: 1d79895aef18 ("sk_msg: Always cancel strp work before freeing the psock") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
We might have never enabled (started) the psock's parser, in which case it
will not get stopped when destroying the psock. This leads to a warning
when trying to cancel parser's work from psock's deferred destructor:

[  405.325769] WARNING: CPU: 1 PID: 3216 at net/strparser/strparser.c:526 strp_done+0x3c/0x40
[  405.326712] Modules linked in: [last unloaded: test_bpf]
[  405.327359] CPU: 1 PID: 3216 Comm: kworker/1:164 Tainted: G        W         5.0.0 #42
[  405.328294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20180531_142017-buildhw-08.phx2.fedoraproject.org-1.fc28 04/01/2014
[  405.329712] Workqueue: events sk_psock_destroy_deferred
[  405.330254] RIP: 0010:strp_done+0x3c/0x40
[  405.330706] Code: 28 e8 b8 d5 6b ff 48 8d bb 80 00 00 00 e8 9c d5 6b ff 48 8b 7b 18 48 85 ff 74 0d e8 1e a5 e8 ff 48 c7 43 18 00 00 00 00 5b c3 <0f> 0b eb cf 66 66 66 66 90 55 89 f5 53 48 89 fb 48 83 c7 28 e8 0b
[  405.332862] RSP: 0018:ffffc900026bbe50 EFLAGS: 00010246
[  405.333482] RAX: ffffffff819323e0 RBX: ffff88812cb83640 RCX: ffff88812cb829e8
[  405.334228] RDX: 0000000000000001 RSI: ffff88812cb837e8 RDI: ffff88812cb83640
[  405.335366] RBP: ffff88813fd22680 R08: 0000000000000000 R09: 000073746e657665
[  405.336472] R10: 8080808080808080 R11: 0000000000000001 R12: ffff88812cb83600
[  405.337760] R13: 0000000000000000 R14: ffff88811f401780 R15: ffff88812cb837e8
[  405.338777] FS:  0000000000000000(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
[  405.339903] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  405.340821] CR2: 00007fb11489a6b8 CR3: 000000012d4d6000 CR4: 00000000000406e0
[  405.341981] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  405.343131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  405.344415] Call Trace:
[  405.344821]  sk_psock_destroy_deferred+0x23/0x1b0
[  405.345585]  process_one_work+0x1ae/0x3e0
[  405.346110]  worker_thread+0x3c/0x3b0
[  405.346576]  ? pwq_unbound_release_workfn+0xd0/0xd0
[  405.347187]  kthread+0x11d/0x140
[  405.347601]  ? __kthread_parkme+0x80/0x80
[  405.348108]  ret_from_fork+0x35/0x40
[  405.348566] ---[ end trace a4a3af4026a327d4 ]---

Stop psock's parser just before canceling its work.

Fixes: 1d79895aef18 ("sk_msg: Always cancel strp work before freeing the psock")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08T23:00:17+00:00 David S. Miller davem@davemloft.net 2019-02-08T23:00:17+00:00 a655fe9f194842693258f43b5382855db1c2f654 An ipvlan bug fix in 'net' conflicted with the abstraction away of the IPV6 specific support in 'net-next'. Similarly, a bug fix for mlx5 in 'net' conflicted with the flow action conversion in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net> 
An ipvlan bug fix in 'net' conflicted with the abstraction away
of the IPV6 specific support in 'net-next'.

Similarly, a bug fix for mlx5 in 'net' conflicted with the flow
action conversion in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
sk_msg: Always cancel strp work before freeing the psock 2019-01-28T23:05:03+00:00 Jakub Sitnicki jakub@cloudflare.com 2019-01-28T09:13:35+00:00 1d79895aef18fa05789995d86d523c9b2ee58a02 Despite having stopped the parser, we still need to deinitialize it by calling strp_done so that it cancels its work. Otherwise the worker thread can run after we have freed the parser, and attempt to access its workqueue resulting in a use-after-free: ================================================================== BUG: KASAN: use-after-free in pwq_activate_delayed_work+0x1b/0x1d0 Read of size 8 at addr ffff888069975240 by task kworker/u2:2/93 CPU: 0 PID: 93 Comm: kworker/u2:2 Not tainted 5.0.0-rc2-00335-g28f9d1a3d4fe-dirty #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 Workqueue: (null) (kstrp) Call Trace: print_address_description+0x6e/0x2b0 ? pwq_activate_delayed_work+0x1b/0x1d0 kasan_report+0xfd/0x177 ? pwq_activate_delayed_work+0x1b/0x1d0 ? pwq_activate_delayed_work+0x1b/0x1d0 pwq_activate_delayed_work+0x1b/0x1d0 ? process_one_work+0x4aa/0x660 pwq_dec_nr_in_flight+0x9b/0x100 worker_thread+0x82/0x680 ? process_one_work+0x660/0x660 kthread+0x1b9/0x1e0 ? __kthread_create_on_node+0x250/0x250 ret_from_fork+0x1f/0x30 Allocated by task 111: sk_psock_init+0x3c/0x1b0 sock_map_link.isra.2+0x103/0x4b0 sock_map_update_common+0x94/0x270 sock_map_update_elem+0x145/0x160 __se_sys_bpf+0x152e/0x1e10 do_syscall_64+0xb2/0x3e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 112: kfree+0x7f/0x140 process_one_work+0x40b/0x660 worker_thread+0x82/0x680 kthread+0x1b9/0x1e0 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff888069975180 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 192 bytes inside of 512-byte region [ffff888069975180, ffff888069975380) The buggy address belongs to the page: page:ffffea0001a65d00 count:1 mapcount:0 mapping:ffff88806d401280 index:0x0 compound_mapcount: 0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000200 ffff88806d401280 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888069975100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888069975180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888069975200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888069975280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888069975300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/netdev/CAJPywTLwgXNEZ2dZVoa=udiZmtrWJ0q5SuBW64aYs0Y1khXX3A@mail.gmail.com Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
Despite having stopped the parser, we still need to deinitialize it
by calling strp_done so that it cancels its work. Otherwise the worker
thread can run after we have freed the parser, and attempt to access
its workqueue resulting in a use-after-free:

==================================================================
BUG: KASAN: use-after-free in pwq_activate_delayed_work+0x1b/0x1d0
Read of size 8 at addr ffff888069975240 by task kworker/u2:2/93

CPU: 0 PID: 93 Comm: kworker/u2:2 Not tainted 5.0.0-rc2-00335-g28f9d1a3d4fe-dirty #14
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
Workqueue:            (null) (kstrp)
Call Trace:
 print_address_description+0x6e/0x2b0
 ? pwq_activate_delayed_work+0x1b/0x1d0
 kasan_report+0xfd/0x177
 ? pwq_activate_delayed_work+0x1b/0x1d0
 ? pwq_activate_delayed_work+0x1b/0x1d0
 pwq_activate_delayed_work+0x1b/0x1d0
 ? process_one_work+0x4aa/0x660
 pwq_dec_nr_in_flight+0x9b/0x100
 worker_thread+0x82/0x680
 ? process_one_work+0x660/0x660
 kthread+0x1b9/0x1e0
 ? __kthread_create_on_node+0x250/0x250
 ret_from_fork+0x1f/0x30

Allocated by task 111:
 sk_psock_init+0x3c/0x1b0
 sock_map_link.isra.2+0x103/0x4b0
 sock_map_update_common+0x94/0x270
 sock_map_update_elem+0x145/0x160
 __se_sys_bpf+0x152e/0x1e10
 do_syscall_64+0xb2/0x3e0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 112:
 kfree+0x7f/0x140
 process_one_work+0x40b/0x660
 worker_thread+0x82/0x680
 kthread+0x1b9/0x1e0
 ret_from_fork+0x1f/0x30

The buggy address belongs to the object at ffff888069975180
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 192 bytes inside of
 512-byte region [ffff888069975180, ffff888069975380)
The buggy address belongs to the page:
page:ffffea0001a65d00 count:1 mapcount:0 mapping:ffff88806d401280 index:0x0 compound_mapcount: 0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000200 ffff88806d401280
raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888069975100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888069975180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888069975200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888069975280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888069975300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Reported-by: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/netdev/CAJPywTLwgXNEZ2dZVoa=udiZmtrWJ0q5SuBW64aYs0Y1khXX3A@mail.gmail.com
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Optimize sk_msg_clone() by data merge to end dst sg entry 2019-01-17T19:42:26+00:00 Vakul Garg vakul.garg@nxp.com 2019-01-16T01:42:44+00:00 fda497e5f5b89ac3b2b3715e2571021c2ad55234 Function sk_msg_clone has been modified to merge the data from source sg entry to destination sg entry if the cloned data resides in same page and is contiguous to the end entry of destination sk_msg. This improves kernel tls throughput to the tune of 10%. When the user space tls application calls sendmsg() with MSG_MORE, it leads to calling sk_msg_clone() with new data being cloned placed continuous to previously cloned data. Without this optimization, a new SG entry in the destination sk_msg i.e. rec->msg_plaintext in tls_clone_plaintext_msg() gets used. This leads to exhaustion of sg entries in rec->msg_plaintext even before a full 16K of allowable record data is accumulated. Hence we lose oppurtunity to encrypt and send a full 16K record. With this patch, the kernel tls can accumulate full 16K of record data irrespective of the size of data passed in sendmsg() with MSG_MORE. Signed-off-by: Vakul Garg <vakul.garg@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Function sk_msg_clone has been modified to merge the data from source sg
entry to destination sg entry if the cloned data resides in same page
and is contiguous to the end entry of destination sk_msg. This improves
kernel tls throughput to the tune of 10%.

When the user space tls application calls sendmsg() with MSG_MORE, it leads
to calling sk_msg_clone() with new data being cloned placed continuous to
previously cloned data. Without this optimization, a new SG entry in
the destination sk_msg i.e. rec->msg_plaintext in tls_clone_plaintext_msg()
gets used. This leads to exhaustion of sg entries in rec->msg_plaintext
even before a full 16K of allowable record data is accumulated. Hence we
lose oppurtunity to encrypt and send a full 16K record.

With this patch, the kernel tls can accumulate full 16K of record data
irrespective of the size of data passed in sendmsg() with MSG_MORE.

Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>