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d468e4775c
It is possible to build a plaintext buffer using push helper that is larger
than the allocated encrypt buffer. When this record is pushed to crypto
layers this can result in a NULL pointer dereference because the crypto
API expects the encrypt buffer is large enough to fit the plaintext
buffer. Kernel splat below.
To resolve catch the cases this can happen and split the buffer into two
records to send individually. Unfortunately, there is still one case to
handle where the split creates a zero sized buffer. In this case we merge
the buffers and unmark the split. This happens when apply is zero and user
pushed data beyond encrypt buffer. This fixes the original case as well
because the split allocated an encrypt buffer larger than the plaintext
buffer and the merge simply moves the pointers around so we now have
a reference to the new (larger) encrypt buffer.
Perhaps its not ideal but it seems the best solution for a fixes branch
and avoids handling these two cases, (a) apply that needs split and (b)
non apply case. The are edge cases anyways so optimizing them seems not
necessary unless someone wants later in next branches.
[ 306.719107] BUG: kernel NULL pointer dereference, address: 0000000000000008
[...]
[ 306.747260] RIP: 0010:scatterwalk_copychunks+0x12f/0x1b0
[...]
[ 306.770350] Call Trace:
[ 306.770956] scatterwalk_map_and_copy+0x6c/0x80
[ 306.772026] gcm_enc_copy_hash+0x4b/0x50
[ 306.772925] gcm_hash_crypt_remain_continue+0xef/0x110
[ 306.774138] gcm_hash_crypt_continue+0xa1/0xb0
[ 306.775103] ? gcm_hash_crypt_continue+0xa1/0xb0
[ 306.776103] gcm_hash_assoc_remain_continue+0x94/0xa0
[ 306.777170] gcm_hash_assoc_continue+0x9d/0xb0
[ 306.778239] gcm_hash_init_continue+0x8f/0xa0
[ 306.779121] gcm_hash+0x73/0x80
[ 306.779762] gcm_encrypt_continue+0x6d/0x80
[ 306.780582] crypto_gcm_encrypt+0xcb/0xe0
[ 306.781474] crypto_aead_encrypt+0x1f/0x30
[ 306.782353] tls_push_record+0x3b9/0xb20 [tls]
[ 306.783314] ? sk_psock_msg_verdict+0x199/0x300
[ 306.784287] bpf_exec_tx_verdict+0x3f2/0x680 [tls]
[ 306.785357] tls_sw_sendmsg+0x4a3/0x6a0 [tls]
test_sockmap test signature to trigger bug,
[TEST]: (1, 1, 1, sendmsg, pass,redir,start 1,end 2,pop (1,2),ktls,):
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.