linux-toradex.git/net/tls, branch v5.18

tls: Fix context leak on tls_device_down

2022-05-12T17:01:36+00:00

The commit cited below claims to fix a use-after-free condition after
tls_device_down. Apparently, the description wasn't fully accurate. The
context stayed alive, but ctx->netdev became NULL, and the offload was
torn down without a proper fallback, so a bug was present, but a
different kind of bug.

Due to misunderstanding of the issue, the original patch dropped the
refcount_dec_and_test line for the context to avoid the alleged
premature deallocation. That line has to be restored, because it matches
the refcount_inc_not_zero from the same function, otherwise the contexts
that survived tls_device_down are leaked.

This patch fixes the described issue by restoring refcount_dec_and_test.
After this change, there is no leak anymore, and the fallback to
software kTLS still works.

Fixes: c55dcdd435aa ("net/tls: Fix use-after-free after the TLS device goes down and up")
Signed-off-by: Maxim Mikityanskiy 
Reviewed-by: Tariq Toukan 
Link: https://lore.kernel.org/r/20220512091830.678684-1-maximmi@nvidia.com
Signed-off-by: Jakub Kicinski

tls: Skip tls_append_frag on zero copy size

2022-04-27T22:25:20+00:00

Calling tls_append_frag when max_open_record_len == record->len might
add an empty fragment to the TLS record if the call happens to be on the
page boundary. Normally tls_append_frag coalesces the zero-sized
fragment to the previous one, but not if it's on page boundary.

If a resync happens then, the mlx5 driver posts dump WQEs in
tx_post_resync_dump, and the empty fragment may become a data segment
with byte_count == 0, which will confuse the NIC and lead to a CQE
error.

This commit fixes the described issue by skipping tls_append_frag on
zero size to avoid adding empty fragments. The fix is not in the driver,
because an empty fragment is hardly the desired behavior.

Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Maxim Mikityanskiy 
Reviewed-by: Tariq Toukan 
Link: https://lore.kernel.org/r/20220426154949.159055-1-maximmi@nvidia.com
Signed-off-by: Jakub Kicinski

net/tls: fix slab-out-of-bounds bug in decrypt_internal

2022-04-01T10:53:35+00:00

The memory size of tls_ctx->rx.iv for AES128-CCM is 12 setting in
tls_set_sw_offload(). The return value of crypto_aead_ivsize()
for "ccm(aes)" is 16. So memcpy() require 16 bytes from 12 bytes
memory space will trigger slab-out-of-bounds bug as following:

==================================================================
BUG: KASAN: slab-out-of-bounds in decrypt_internal+0x385/0xc40 [tls]
Read of size 16 at addr ffff888114e84e60 by task tls/10911

Call Trace:
 
 dump_stack_lvl+0x34/0x44
 print_report.cold+0x5e/0x5db
 ? decrypt_internal+0x385/0xc40 [tls]
 kasan_report+0xab/0x120
 ? decrypt_internal+0x385/0xc40 [tls]
 kasan_check_range+0xf9/0x1e0
 memcpy+0x20/0x60
 decrypt_internal+0x385/0xc40 [tls]
 ? tls_get_rec+0x2e0/0x2e0 [tls]
 ? process_rx_list+0x1a5/0x420 [tls]
 ? tls_setup_from_iter.constprop.0+0x2e0/0x2e0 [tls]
 decrypt_skb_update+0x9d/0x400 [tls]
 tls_sw_recvmsg+0x3c8/0xb50 [tls]

Allocated by task 10911:
 kasan_save_stack+0x1e/0x40
 __kasan_kmalloc+0x81/0xa0
 tls_set_sw_offload+0x2eb/0xa20 [tls]
 tls_setsockopt+0x68c/0x700 [tls]
 __sys_setsockopt+0xfe/0x1b0

Replace the crypto_aead_ivsize() with prot->iv_size + prot->salt_size
when memcpy() iv value in TLS_1_3_VERSION scenario.

Fixes: f295b3ae9f59 ("net/tls: Add support of AES128-CCM based ciphers")
Signed-off-by: Ziyang Xuan 
Reviewed-by: Jakub Kicinski 
Signed-off-by: David S. Miller

net/tls: optimize judgement processes in tls_set_device_offload()

2022-03-21T21:58:16+00:00

It is known that priority setting HW offload when set tls TX/RX offload
by setsockopt(). Check netdevice whether support NETIF_F_HW_TLS_TX or
not at the later stages in the whole tls_set_device_offload() process,
some memory allocations have been done before that. We must release those
memory and return error if we judge the netdevice not support
NETIF_F_HW_TLS_TX. It is redundant.

Move NETIF_F_HW_TLS_TX judgement forward, and move start_marker_record
and offload_ctx memory allocation back slightly. Thus, we can get
simpler exception handling process.

Signed-off-by: Ziyang Xuan 
Signed-off-by: Jakub Kicinski

net/tls: remove unnecessary jump instructions in do_tls_setsockopt_conf()

2022-03-21T21:58:13+00:00

Avoid using "goto" jump instruction unconditionally when we
can return directly. Remove unnecessary jump instructions in
do_tls_setsockopt_conf().

Signed-off-by: Ziyang Xuan 
Signed-off-by: Jakub Kicinski

tls: cap the output scatter list to something reasonable

2022-02-04T10:14:07+00:00

TLS recvmsg() passes user pages as destination for decrypt.
The decrypt operation is repeated record by record, each
record being 16kB, max. TLS allocates an sg_table and uses
iov_iter_get_pages() to populate it with enough pages to
fit the decrypted record.

Even though we decrypt a single message at a time we size
the sg_table based on the entire length of the iovec.
This leads to unnecessarily large allocations, risking
triggering OOM conditions.

Use iov_iter_truncate() / iov_iter_reexpand() to construct
a "capped" version of iov_iter_npages(). Alternatively we
could parametrize iov_iter_npages() to take the size as
arg instead of using i->count, or do something else..

Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

net/tls: Fix another skb memory leak when running kTLS traffic

2022-01-17T13:07:47+00:00

This patch is a followup to
commit ffef737fd037 ("net/tls: Fix skb memory leak when running kTLS traffic")

Which was missing another sk_defer_free_flush() call in
tls_sw_splice_read().

Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released")
Signed-off-by: Gal Pressman 
Signed-off-by: David S. Miller

net/tls: Fix skb memory leak when running kTLS traffic

2022-01-08T02:42:18+00:00

The cited Fixes commit introduced a memory leak when running kTLS
traffic (with/without hardware offloads).
I'm running nginx on the server side and wrk on the client side and get
the following:

  unreferenced object 0xffff8881935e9b80 (size 224):
  comm "softirq", pid 0, jiffies 4294903611 (age 43.204s)
  hex dump (first 32 bytes):
    80 9b d0 36 81 88 ff ff 00 00 00 00 00 00 00 00  ...6............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000efe2a999>] build_skb+0x1f/0x170
    [<00000000ef521785>] mlx5e_skb_from_cqe_mpwrq_linear+0x2bc/0x610 [mlx5_core]
    [<00000000945d0ffe>] mlx5e_handle_rx_cqe_mpwrq+0x264/0x9e0 [mlx5_core]
    [<00000000cb675b06>] mlx5e_poll_rx_cq+0x3ad/0x17a0 [mlx5_core]
    [<0000000018aac6a9>] mlx5e_napi_poll+0x28c/0x1b60 [mlx5_core]
    [<000000001f3369d1>] __napi_poll+0x9f/0x560
    [<00000000cfa11f72>] net_rx_action+0x357/0xa60
    [<000000008653b8d7>] __do_softirq+0x282/0x94e
    [<00000000644923c6>] __irq_exit_rcu+0x11f/0x170
    [<00000000d4085f8f>] irq_exit_rcu+0xa/0x20
    [<00000000d412fef4>] common_interrupt+0x7d/0xa0
    [<00000000bfb0cebc>] asm_common_interrupt+0x1e/0x40
    [<00000000d80d0890>] default_idle+0x53/0x70
    [<00000000f2b9780e>] default_idle_call+0x8c/0xd0
    [<00000000c7659e15>] do_idle+0x394/0x450

I'm not familiar with these areas of the code, but I've added this
sk_defer_free_flush() to tls_sw_recvmsg() based on a hunch and it
resolved the issue.

Fixes: f35f821935d8 ("tcp: defer skb freeing after socket lock is released")
Signed-off-by: Gal Pressman 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20220102081253.9123-1-gal@nvidia.com
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-12-02T19:44:56+00:00

Signed-off-by: Jakub Kicinski

net/tls: simplify the tls_set_sw_offload function

2021-11-30T11:58:34+00:00

Assigning crypto_info variables in advance can simplify the logic
of accessing value and move related local variables to a smaller
scope.

Signed-off-by: Tianjia Zhang 
Reviewed-by: Jakub Kicinski 
Signed-off-by: David S. Miller