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path: root/fs/ubifs/auth.c
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2019-09-15ubifs: Fix memory leak in __ubifs_node_verify_hmac error pathWenwen Wang
In __ubifs_node_verify_hmac(), 'hmac' is allocated through kmalloc(). However, it is not deallocated in the following execution if ubifs_node_calc_hmac() fails, leading to a memory leak bug. To fix this issue, free 'hmac' before returning the error. Fixes: 49525e5eecca ("ubifs: Add helper functions for authentication support") Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-07-08ubifs: support offline signed imagesSascha Hauer
HMACs can only be generated on the system the UBIFS image is running on. To support offline signed images we add a PKCS#7 signature to the UBIFS image which can be created by mkfs.ubifs. Both the master node and the superblock need to be authenticated, during normal runtime both are protected with HMACs. For offline signature support however only a single signature is desired. We add a signature covering the superblock node directly behind it. To protect the master node a hash of the master node is added to the superblock which is used when the master node doesn't contain a HMAC. Transition to a read/write filesystem is also supported. During transition first the master node is rewritten with a HMAC (implicitly, it is written anyway as the FS is marked dirty). Afterwards the superblock is rewritten with a HMAC. Once after the image has been mounted read/write it is HMAC only, the signature is no longer required or even present on the filesystem. In an offline signed image the master node is authenticated by the superblock. In a transition to r/w we have to make sure that the master node is rewritten before the superblock node. In this case the master node gets a HMAC and its authenticity no longer depends on the superblock node. There are some cases in which the current code first writes the superblock node though, so with this patch writing of the superblock node is delayed until the master node is written. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-05-12Merge tag 'upstream-5.2-rc1' of ↵Linus Torvalds
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/rw/ubifs Pull UBI/UBIFS updates from Richard Weinberger: - fscrypt framework usage updates - One huge fix for xattr unlink - Cleanup of fscrypt ifdefs - Fix for our new UBIFS auth feature * tag 'upstream-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/rw/ubifs: ubi: wl: Fix uninitialized variable ubifs: Drop unnecessary setting of zbr->znode ubifs: Remove ifdefs around CONFIG_UBIFS_ATIME_SUPPORT ubifs: Remove #ifdef around CONFIG_FS_ENCRYPTION ubifs: Limit number of xattrs per inode ubifs: orphan: Handle xattrs like files ubifs: journal: Handle xattrs like files ubifs: find.c: replace swap function with built-in one ubifs: Do not skip hash checking in data nodes ubifs: work around high stack usage with clang ubifs: remove unused function __ubifs_shash_final ubifs: remove unnecessary #ifdef around fscrypt_ioctl_get_policy() ubifs: remove unnecessary calls to set up directory key
2019-05-07ubifs: work around high stack usage with clangArnd Bergmann
Building this file with clang can result in large stack usage as seen from this warning: fs/ubifs/auth.c:78:5: error: stack frame size of 1152 bytes in function 'ubifs_prepare_auth_node' The problem is that inlining ubifs_hash_calc_hmac() leads to two SHASH_DESC_ON_STACK() blocks in the same function, and clang for some reason does not reuse the stack space as it should. Putting the first declaration into a separate basic block avoids this problem and reduces the stack allocation to 640 bytes. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-05-07ubifs: remove unused function __ubifs_shash_finalYueHaibing
There is no callers in tree, and can be removed. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Richard Weinberger <richard@nod.at>
2019-04-25crypto: shash - remove shash_desc::flagsEric Biggers
The flags field in 'struct shash_desc' never actually does anything. The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP. However, no shash algorithm ever sleeps, making this flag a no-op. With this being the case, inevitably some users who can't sleep wrongly pass MAY_SLEEP. These would all need to be fixed if any shash algorithm actually started sleeping. For example, the shash_ahash_*() functions, which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP from the ahash API to the shash API. However, the shash functions are called under kmap_atomic(), so actually they're assumed to never sleep. Even if it turns out that some users do need preemption points while hashing large buffers, we could easily provide a helper function crypto_shash_update_large() which divides the data into smaller chunks and calls crypto_shash_update() and cond_resched() for each chunk. It's not necessary to have a flag in 'struct shash_desc', nor is it necessary to make individual shash algorithms aware of this at all. Therefore, remove shash_desc::flags, and document that the crypto_shash_*() functions can be called from any context. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-11-20crypto: drop mask=CRYPTO_ALG_ASYNC from 'shash' tfm allocationsEric Biggers
'shash' algorithms are always synchronous, so passing CRYPTO_ALG_ASYNC in the mask to crypto_alloc_shash() has no effect. Many users therefore already don't pass it, but some still do. This inconsistency can cause confusion, especially since the way the 'mask' argument works is somewhat counterintuitive. Thus, just remove the unneeded CRYPTO_ALG_ASYNC flags. This patch shouldn't change any actual behavior. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-10-23ubifs: Add helper functions for authentication supportSascha Hauer
This patch adds the various helper functions needed for authentication support. We need functions to hash nodes, to embed HMACs into a node and to compare hashes and HMACs. Most functions first check if this filesystem is authenticated and bail out early if not, which makes the functions safe to be called with disabled authentication. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>