kernel/git/stable/linux.git/drivers/md/dm-crypt.c, branch master

dm-crypt: fix a tiny race condition in crypt_dec_pending

2026-09-01T11:24:50+00:00

crypt_dec_pending reads io->error before calling atomic_dec_and_test. Another context, for example crypt_endio called from an interrupt, may set io->error and drop its reference between the read and the decrement. crypt_dec_pending then drops the last reference and completes the bio with the stale status - so a read that failed and was never decrypted, or a write that failed, is reported as successful. The read was placed before the decrement by commit b35f8caa0890 ("dm crypt: wait for endio to complete before destruction"), because that commit freed dm_crypt_io before calling bio_endio. This is no longer the case, dm_crypt_io lives in the per-bio data now. Read io->error after atomic_dec_and_test instead. atomic_dec_and_test is fully ordered, so no additional barrier is needed. Fixes: b35f8caa0890 ("dm crypt: wait for endio to complete before destruction") Cc: stable@vger.kernel.org Reviewed-by: Jose Fernandez (Anthropic) Signed-off-by: Ben Cressey Assisted-by: Claude:unspecified Signed-off-by: Mikulas Patocka

dm-crypt: Make crypt_iv_operations::post return void

2026-03-30T10:06:33+00:00

Since all implementations of crypt_iv_operations::post now return 0, change the return type to void. Signed-off-by: Eric Biggers Signed-off-by: Mikulas Patocka

dm: provide helper to set stacked limits

2026-03-27T21:19:17+00:00

There are multiple device mappers that set up their stacking limits exactly the same for the logical, physical and minimum IO queue limits. Provide a helper for it. Signed-off-by: Keith Busch Signed-off-by: Mikulas Patocka

dm-crypt: Make crypt_iv_operations::wipe return void

2026-03-23T16:51:27+00:00

Since all implementations of crypt_iv_operations::wipe now return 0, change the return type to void. Signed-off-by: Eric Biggers Signed-off-by: Mikulas Patocka

dm-crypt: Reimplement elephant diffuser using AES library

2026-03-23T16:51:13+00:00

Simplify and optimize dm-crypt's implementation of Bitlocker's "elephant diffuser" to use the AES library instead of an "ecb(aes)" crypto_skcipher. Note: struct aes_enckey is fixed-size, so it could be embedded directly in struct iv_elephant_private. But I kept it as a separate allocation so that the size of struct crypt_config doesn't increase. The elephant diffuser is rarely used in dm-crypt. Signed-off-by: Eric Biggers Signed-off-by: Mikulas Patocka

Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses

2026-02-22T16:26:33+00:00

Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds

Convert 'alloc_flex' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This is the exact same thing as the 'alloc_obj()' version, only much smaller because there are a lot fewer users of the *alloc_flex() interface. As with alloc_obj() version, this was done entirely with mindless brute force, using the same script, except using 'flex' in the pattern rather than 'objs*'. Signed-off-by: Linus Torvalds

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

dm-crypt: Adjust crypt_alloc_tfms_aead() allocation type

2026-02-19T18:05:20+00:00

In preparation for making the kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.) The assigned type is "struct crypto_skcipher **" but the returned type will be "struct crypto_aead **". These are the same allocation size (pointer size), but the types don't match. Adjust the allocation type to match the assignment. Link: https://patch.msgid.link/20250426061629.work.266-kees@kernel.org Signed-off-by: Kees Cook