kernel/linux.git/drivers/md/dm-crypt.c, branch v5.15.208

dm-crypt: track tag_offset in convert_context

2025-03-13T11:50:28+00:00

commit 8b8f8037765757861f899ed3a2bfb34525b5c065 upstream. dm-crypt uses tag_offset to index the integrity metadata for each crypt sector. When the initial crypt_convert() returns BLK_STS_DEV_RESOURCE, dm-crypt will try to continue the crypt/decrypt procedure in a kworker. However, it resets tag_offset as zero instead of using the tag_offset related with current sector. It may return unexpected data when using random IV or return unexpected integrity related error. Fix the problem by tracking tag_offset in per-IO convert_context. Therefore, when the crypt/decrypt procedure continues in a kworker, it could use the next tag_offset saved in convert_context. Fixes: 8abec36d1274 ("dm crypt: do not wait for backlogged crypto request completion in softirq") Cc: stable@vger.kernel.org Signed-off-by: Hou Tao Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman

dm-crypt: don't update io->sector after kcryptd_crypt_write_io_submit()

2025-03-13T11:50:28+00:00

commit 9fdbbdbbc92b1474a87b89f8b964892a63734492 upstream. The updates of io->sector are the leftovers when dm-crypt allocated pages for partial write request. However, since commit cf2f1abfbd0db ("dm crypt: don't allocate pages for a partial request"), there is no partial request anymore. After the introduction of write request rb-tree, the updates of io->sectors may interfere the insertion procedure, because ->sectors of these write requests which have already been added in the rb-tree may be changed during the insertion of new write request. Fix it by removing these buggy updates of io->sectors. Considering these updates only effect the write request rb-tree, the commit which introduces the write request rb-tree is used as the fix tag. Fixes: b3c5fd305249 ("dm crypt: sort writes") Cc: stable@vger.kernel.org Signed-off-by: Hou Tao Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman

dm-crypt, dm-verity: disable tasklets

2024-10-22T13:40:41+00:00

commit 0a9bab391e336489169b95cb0d4553d921302189 upstream. Tasklets have an inherent problem with memory corruption. The function tasklet_action_common calls tasklet_trylock, then it calls the tasklet callback and then it calls tasklet_unlock. If the tasklet callback frees the structure that contains the tasklet or if it calls some code that may free it, tasklet_unlock will write into free memory. The commits 8e14f610159d and d9a02e016aaf try to fix it for dm-crypt, but it is not a sufficient fix and the data corruption can still happen [1]. There is no fix for dm-verity and dm-verity will write into free memory with every tasklet-processed bio. There will be atomic workqueues implemented in the kernel 6.9 [2]. They will have better interface and they will not suffer from the memory corruption problem. But we need something that stops the memory corruption now and that can be backported to the stable kernels. So, I'm proposing this commit that disables tasklets in both dm-crypt and dm-verity. This commit doesn't remove the tasklet support, because the tasklet code will be reused when atomic workqueues will be implemented. [1] https://lore.kernel.org/all/d390d7ee-f142-44d3-822a-87949e14608b@suse.de/T/ [2] https://lore.kernel.org/lkml/20240130091300.2968534-1-tj@kernel.org/ Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Fixes: 39d42fa96ba1b ("dm crypt: add flags to optionally bypass kcryptd workqueues") Fixes: 5721d4e5a9cdb ("dm verity: Add optional "try_verify_in_tasklet" feature") Signed-off-by: Mike Snitzer Signed-off-by: Saeed Mirzamohammadi Signed-off-by: Greg Kroah-Hartman

dm-verity, dm-crypt: align "struct bvec_iter" correctly

2024-03-26T22:21:13+00:00

[ Upstream commit 787f1b2800464aa277236a66eb3c279535edd460 ] "struct bvec_iter" is defined with the __packed attribute, so it is aligned on a single byte. On X86 (and on other architectures that support unaligned addresses in hardware), "struct bvec_iter" is accessed using the 8-byte and 4-byte memory instructions, however these instructions are less efficient if they operate on unaligned addresses. (on RISC machines that don't have unaligned access in hardware, GCC generates byte-by-byte accesses that are very inefficient - see [1]) This commit reorders the entries in "struct dm_verity_io" and "struct convert_context", so that "struct bvec_iter" is aligned on 8 bytes. [1] https://lore.kernel.org/all/ZcLuWUNRZadJr0tQ@fedora/T/ Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin

dm-crypt: don't modify the data when using authenticated encryption

2024-03-01T12:21:48+00:00

commit 50c70240097ce41fe6bce6478b80478281e4d0f7 upstream. It was said that authenticated encryption could produce invalid tag when the data that is being encrypted is modified [1]. So, fix this problem by copying the data into the clone bio first and then encrypt them inside the clone bio. This may reduce performance, but it is needed to prevent the user from corrupting the device by writing data with O_DIRECT and modifying them at the same time. [1] https://lore.kernel.org/all/20240207004723.GA35324@sol.localdomain/T/ Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm crypt: avoid accessing uninitialized tasklet

2023-03-30T10:48:00+00:00

commit d9a02e016aaf5a57fb44e9a5e6da8ccd3b9e2e70 upstream. When neither "no_read_workqueue" nor "no_write_workqueue" are enabled, tasklet_trylock() in crypt_dec_pending() may still return false due to an uninitialized state, and dm-crypt will unnecessarily do io completion in io_queue workqueue instead of current context. Fix this by adding an 'in_tasklet' flag to dm_crypt_io struct and initialize it to false in crypt_io_init(). Set this flag to true in kcryptd_queue_crypt() before calling tasklet_schedule(). If set crypt_dec_pending() will punt io completion to a workqueue. This also nicely avoids the tasklet_trylock/unlock hack when tasklets aren't in use. Fixes: 8e14f610159d ("dm crypt: do not call bio_endio() from the dm-crypt tasklet") Cc: stable@vger.kernel.org Reported-by: Hou Tao Suggested-by: Ignat Korchagin Reviewed-by: Ignat Korchagin Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm crypt: add cond_resched() to dmcrypt_write()

2023-03-30T10:48:00+00:00

commit fb294b1c0ba982144ca467a75e7d01ff26304e2b upstream. The loop in dmcrypt_write may be running for unbounded amount of time, thus we need cond_resched() in it. This commit fixes the following warning: [ 3391.153255][ C12] watchdog: BUG: soft lockup - CPU#12 stuck for 23s! [dmcrypt_write/2:2897] ... [ 3391.387210][ C12] Call trace: [ 3391.390338][ C12] blk_attempt_bio_merge.part.6+0x38/0x158 [ 3391.395970][ C12] blk_attempt_plug_merge+0xc0/0x1b0 [ 3391.401085][ C12] blk_mq_submit_bio+0x398/0x550 [ 3391.405856][ C12] submit_bio_noacct+0x308/0x380 [ 3391.410630][ C12] dmcrypt_write+0x1e4/0x208 [dm_crypt] [ 3391.416005][ C12] kthread+0x130/0x138 [ 3391.419911][ C12] ret_from_fork+0x10/0x18 Reported-by: yangerkun Fixes: dc2676210c42 ("dm crypt: offload writes to thread") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm crypt: make printing of the key constant-time

2022-06-06T06:43:40+00:00

commit 567dd8f34560fa221a6343729474536aa7ede4fd upstream. The device mapper dm-crypt target is using scnprintf("%02x", cc->key[i]) to report the current key to userspace. However, this is not a constant-time operation and it may leak information about the key via timing, via cache access patterns or via the branch predictor. Change dm-crypt's key printing to use "%c" instead of "%02x". Also introduce hex2asc() that carefully avoids any branching or memory accesses when converting a number in the range 0 ... 15 to an ascii character. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Tested-by: Milan Broz Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm crypt: fix get_key_size compiler warning if !CONFIG_KEYS

2022-04-08T12:23:33+00:00

[ Upstream commit 6fc51504388c1a1a53db8faafe9fff78fccc7c87 ] Explicitly convert unsigned int in the right of the conditional expression to int to match the left side operand and the return type, fixing the following compiler warning: drivers/md/dm-crypt.c:2593:43: warning: signed and unsigned type in conditional expression [-Wsign-compare] Fixes: c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service") Signed-off-by: Aashish Sharma Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin

dm crypt: use in_hardirq() instead of deprecated in_irq()

2021-08-20T20:25:07+00:00

Signed-off-by: Changbin Du Signed-off-by: Mike Snitzer