- Fix an integer underflow in the mpi library
- Improve the crypto library documentation
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Merge tag 'libcrypto-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux
Pull more crypto library updates from Eric Biggers:
"Crypto library fix and documentation update:
- Fix an integer underflow in the mpi library
- Improve the crypto library documentation"
* tag 'libcrypto-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
lib/crypto: docs: Add rst documentation to Documentation/crypto/
docs: kdoc: Expand 'at_least' when creating parameter list
lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()
Yiming reports an integer underflow in mpi_read_raw_from_sgl() when
subtracting "lzeros" from the unsigned "nbytes".
For this to happen, the scatterlist "sgl" needs to occupy more bytes
than the "nbytes" parameter and the first "nbytes + 1" bytes of the
scatterlist must be zero. Under these conditions, the while loop
iterating over the scatterlist will count more zeroes than "nbytes",
subtract the number of zeroes from "nbytes" and cause the underflow.
When commit 2d4d1eea54 ("lib/mpi: Add mpi sgl helpers") originally
introduced the bug, it couldn't be triggered because all callers of
mpi_read_raw_from_sgl() passed a scatterlist whose length was equal to
"nbytes".
However since commit 63ba4d6759 ("KEYS: asymmetric: Use new crypto
interface without scatterlists"), the underflow can now actually be
triggered. When invoking a KEYCTL_PKEY_ENCRYPT system call with a
larger "out_len" than "in_len" and filling the "in" buffer with zeroes,
crypto_akcipher_sync_prep() will create an all-zero scatterlist used for
both the "src" and "dst" member of struct akcipher_request and thereby
fulfil the conditions to trigger the bug:
sys_keyctl()
keyctl_pkey_e_d_s()
asymmetric_key_eds_op()
software_key_eds_op()
crypto_akcipher_sync_encrypt()
crypto_akcipher_sync_prep()
crypto_akcipher_encrypt()
rsa_enc()
mpi_read_raw_from_sgl()
To the user this will be visible as a DoS as the kernel spins forever,
causing soft lockup splats as a side effect.
Fix it.
Reported-by: Yiming Qian <yimingqian591@gmail.com> # off-list
Fixes: 2d4d1eea54 ("lib/mpi: Add mpi sgl helpers")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v4.4+
Reviewed-by: Ignat Korchagin <ignat@linux.win>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/59eca92ff4f87e2081777f1423a0efaaadcfdb39.1776003111.git.lukas@wunner.de
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
count_leading_zeros() is based on fls(), which is defined for x == 0,
contrary to __ffs() family. The comment in crypto/mpi erroneously
states that the function may return undef in such case.
Fix the comment together with the outdated function signature, and now
that COUNT_LEADING_ZEROS_0 is not referenced in the codebase, get rid of
it too.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Yury Norov <ynorov@nvidia.com>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
and so cannot discard significant bits.
In this case the 'unsigned long' value is small enough that the result
is ok.
Detected by an extra check added to min_t().
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix build warnings with W=1 that started appearing after
commit a934a57a42 ("scripts/misc-check: check missing #include
<linux/export.h> when W=1").
While at it, also sort the include lists alphabetically. (Keep
asm/irqflags.h last, as otherwise it doesn't build on alpha.)
This handles all of lib/crypto/, but not arch/*/lib/crypto/. The
exports in arch/*/lib/crypto/ will go away when the code is properly
integrated into lib/crypto/ as planned.
Link: https://lore.kernel.org/r/20250613184814.50173-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
This function is part of the exposed API and should be exported.
Otherwise a modular user would fail to build, e.g., crypto/rsa.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The "err" variable may be returned without an initialized value.
Fixes: 8e3a67f2de ("crypto: lib/mpi - Add error checks to extension")
Signed-off-by: Qianqiang Liu <qianqiang.liu@163.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The remaining functions added by commit
a8ea8bdd9d did not check for memory
allocation errors. Add the checks and change the API to allow errors
to be returned.
Fixes: a8ea8bdd9d ("lib/mpi: Extend the MPI library")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This partially reverts commit a8ea8bdd9d.
Most of it is no longer needed since sm2 has been removed. However,
the following functions have been kept as they have developed other
uses:
mpi_copy
mpi_mod
mpi_test_bit
mpi_set_bit
mpi_rshift
mpi_add
mpi_sub
mpi_addm
mpi_subm
mpi_mul
mpi_mulm
mpi_tdiv_r
mpi_fdiv_r
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We checked that "nlimbs" is non-zero in the outside if statement so delete
the duplicate check here.
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use existing swap() function rather than duplicating its implementation.
./lib/crypto/mpi/mpi-pow.c:211:11-12: WARNING opportunity for swap().
./lib/crypto/mpi/mpi-pow.c:239:12-13: WARNING opportunity for swap().
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9327
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use existing swap() function rather than duplicating its implementation.
./lib/crypto/mpi/ec.c:1291:20-21: WARNING opportunity for swap().
./lib/crypto/mpi/ec.c:1292:20-21: WARNING opportunity for swap().
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9328
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When the mpi_ec_ctx structure is initialized, some fields are not
cleared, causing a crash when referencing the field when the
structure was released. Initially, this issue was ignored because
memory for mpi_ec_ctx is allocated with the __GFP_ZERO flag.
For example, this error will be triggered when calculating the
Za value for SM2 separately.
Fixes: d58bb7e55a ("lib/mpi: Introduce ec implementation to MPI library")
Cc: stable@vger.kernel.org # v6.5
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
During NVMeTCP Authentication a controller can trigger a kernel
oops by specifying the 8192 bit Diffie Hellman group and passing
a correctly sized, but zeroed Diffie Hellamn value.
mpi_cmp_ui() was detecting this if the second parameter was 0,
but 1 is passed from dh_is_pubkey_valid(). This causes the null
pointer u->d to be dereferenced towards the end of mpi_cmp_ui()
Signed-off-by: Mark O'Donovan <shiftee@posteo.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As lib/mpi is mostly used by crypto code, move it under lib/crypto
so that patches touching it get directed to the right mailing list.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
