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2026-04-21Merge tag 'libcrypto-for-linus' of ↵Linus Torvalds
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()
2026-04-14lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()Lukas Wunner
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 2d4d1eea540b ("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 63ba4d67594a ("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: 2d4d1eea540b ("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>
2026-03-23lib: crypto: fix comments for count_leading_zeros()Yury Norov
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>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
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>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
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>
2025-11-24crypto: lib/mpi - use min() instead of min_t()David Laight
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>
2025-06-30lib/crypto: Explicitly include <linux/export.h>Eric Biggers
Fix build warnings with W=1 that started appearing after commit a934a57a42f6 ("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>
2024-11-15crypto: lib/mpi - Export mpi_set_bitHerbert Xu
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>
2024-10-05crypto: lib/mpi - Fix an "Uninitialized scalar variable" issueQianqiang Liu
The "err" variable may be returned without an initialized value. Fixes: 8e3a67f2de87 ("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>
2024-08-17crypto: lib/mpi - Add error checks to extensionHerbert Xu
The remaining functions added by commit a8ea8bdd9df92a0e5db5b43900abb7a288b8a53e did not check for memory allocation errors. Add the checks and change the API to allow errors to be returned. Fixes: a8ea8bdd9df9 ("lib/mpi: Extend the MPI library") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-08-17Revert "lib/mpi: Extend the MPI library"Herbert Xu
This partially reverts commit a8ea8bdd9df92a0e5db5b43900abb7a288b8a53e. 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>
2024-08-10Revert "lib/mpi: Introduce ec implementation to MPI library"Herbert Xu
This reverts commit d58bb7e55a8a65894cc02f27c3e2bf9403e7c40f. It's no longer needed since sm2 has been removed. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-07-13crypto: lib/mpi - delete unnecessary conditionDan Carpenter
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>
2024-06-21crypto: lib/mpi - Use swap() in mpi_powm()Jiapeng Chong
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>
2024-06-21crypto: lib/mpi - Use swap() in mpi_ec_mul_point()Jiapeng Chong
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>
2023-12-22crypto: lib/mpi - Fix unexpected pointer access in mpi_ec_initTianjia Zhang
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: d58bb7e55a8a ("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>
2023-08-11crypto: lib/mpi - avoid null pointer deref in mpi_cmp_ui()Mark O'Donovan
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>
2023-08-11crypto: lib - Move mpi into lib/cryptoHerbert Xu
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>
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