linux/crypto/algif_hash.c

494 lines
10 KiB

crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE) If an AF_ALG socket bound to a hashing algorithm is sent a zero-length message with MSG_MORE set and then recvmsg() is called without first sending another message without MSG_MORE set to end the operation, an oops will occur because the crypto context and result doesn't now get set up in advance because hash_sendmsg() now defers that as long as possible in the hope that it can use crypto_ahash_digest() - and then because the message is zero-length, it the data wrangling loop is skipped. Fix this by handling zero-length sends at the top of the hash_sendmsg() function. If we're not continuing the previous sendmsg(), then just ignore the send (hash_recvmsg() will invent something when called); if we are continuing, then we finalise the request at this point if MSG_MORE is not set to get any error here, otherwise the send is of no effect and can be ignored. Whilst we're at it, remove the code to create a kvmalloc'd scatterlist if we get more than ALG_MAX_PAGES - this shouldn't happen. Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES") Reported-by: syzbot+13a08c0bf4d212766c3c@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b928f705fdeb873a@google.com/ Reported-by: syzbot+14234ccf6d0ef629ec1a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000c047db05fdeb8790@google.com/ Reported-by: syzbot+4e2e47f32607d0f72d43@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000bcca3205fdeb87fb@google.com/ Reported-by: syzbot+472626bb5e7c59fb768f@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b55d8805fdeb8385@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reported-and-tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/427646.1686913832@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-16 12:10:32 +01:00
crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE) If an AF_ALG socket bound to a hashing algorithm is sent a zero-length message with MSG_MORE set and then recvmsg() is called without first sending another message without MSG_MORE set to end the operation, an oops will occur because the crypto context and result doesn't now get set up in advance because hash_sendmsg() now defers that as long as possible in the hope that it can use crypto_ahash_digest() - and then because the message is zero-length, it the data wrangling loop is skipped. Fix this by handling zero-length sends at the top of the hash_sendmsg() function. If we're not continuing the previous sendmsg(), then just ignore the send (hash_recvmsg() will invent something when called); if we are continuing, then we finalise the request at this point if MSG_MORE is not set to get any error here, otherwise the send is of no effect and can be ignored. Whilst we're at it, remove the code to create a kvmalloc'd scatterlist if we get more than ALG_MAX_PAGES - this shouldn't happen. Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES") Reported-by: syzbot+13a08c0bf4d212766c3c@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b928f705fdeb873a@google.com/ Reported-by: syzbot+14234ccf6d0ef629ec1a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000c047db05fdeb8790@google.com/ Reported-by: syzbot+4e2e47f32607d0f72d43@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000bcca3205fdeb87fb@google.com/ Reported-by: syzbot+472626bb5e7c59fb768f@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b55d8805fdeb8385@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reported-and-tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/427646.1686913832@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-16 12:10:32 +01:00
crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE) If an AF_ALG socket bound to a hashing algorithm is sent a zero-length message with MSG_MORE set and then recvmsg() is called without first sending another message without MSG_MORE set to end the operation, an oops will occur because the crypto context and result doesn't now get set up in advance because hash_sendmsg() now defers that as long as possible in the hope that it can use crypto_ahash_digest() - and then because the message is zero-length, it the data wrangling loop is skipped. Fix this by handling zero-length sends at the top of the hash_sendmsg() function. If we're not continuing the previous sendmsg(), then just ignore the send (hash_recvmsg() will invent something when called); if we are continuing, then we finalise the request at this point if MSG_MORE is not set to get any error here, otherwise the send is of no effect and can be ignored. Whilst we're at it, remove the code to create a kvmalloc'd scatterlist if we get more than ALG_MAX_PAGES - this shouldn't happen. Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES") Reported-by: syzbot+13a08c0bf4d212766c3c@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b928f705fdeb873a@google.com/ Reported-by: syzbot+14234ccf6d0ef629ec1a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000c047db05fdeb8790@google.com/ Reported-by: syzbot+4e2e47f32607d0f72d43@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000bcca3205fdeb87fb@google.com/ Reported-by: syzbot+472626bb5e7c59fb768f@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b55d8805fdeb8385@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reported-and-tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/427646.1686913832@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-16 12:10:32 +01:00
crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE) If an AF_ALG socket bound to a hashing algorithm is sent a zero-length message with MSG_MORE set and then recvmsg() is called without first sending another message without MSG_MORE set to end the operation, an oops will occur because the crypto context and result doesn't now get set up in advance because hash_sendmsg() now defers that as long as possible in the hope that it can use crypto_ahash_digest() - and then because the message is zero-length, it the data wrangling loop is skipped. Fix this by handling zero-length sends at the top of the hash_sendmsg() function. If we're not continuing the previous sendmsg(), then just ignore the send (hash_recvmsg() will invent something when called); if we are continuing, then we finalise the request at this point if MSG_MORE is not set to get any error here, otherwise the send is of no effect and can be ignored. Whilst we're at it, remove the code to create a kvmalloc'd scatterlist if we get more than ALG_MAX_PAGES - this shouldn't happen. Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES") Reported-by: syzbot+13a08c0bf4d212766c3c@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b928f705fdeb873a@google.com/ Reported-by: syzbot+14234ccf6d0ef629ec1a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000c047db05fdeb8790@google.com/ Reported-by: syzbot+4e2e47f32607d0f72d43@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000bcca3205fdeb87fb@google.com/ Reported-by: syzbot+472626bb5e7c59fb768f@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b55d8805fdeb8385@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reported-and-tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/427646.1686913832@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-16 12:10:32 +01:00
crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE) If an AF_ALG socket bound to a hashing algorithm is sent a zero-length message with MSG_MORE set and then recvmsg() is called without first sending another message without MSG_MORE set to end the operation, an oops will occur because the crypto context and result doesn't now get set up in advance because hash_sendmsg() now defers that as long as possible in the hope that it can use crypto_ahash_digest() - and then because the message is zero-length, it the data wrangling loop is skipped. Fix this by handling zero-length sends at the top of the hash_sendmsg() function. If we're not continuing the previous sendmsg(), then just ignore the send (hash_recvmsg() will invent something when called); if we are continuing, then we finalise the request at this point if MSG_MORE is not set to get any error here, otherwise the send is of no effect and can be ignored. Whilst we're at it, remove the code to create a kvmalloc'd scatterlist if we get more than ALG_MAX_PAGES - this shouldn't happen. Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES") Reported-by: syzbot+13a08c0bf4d212766c3c@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b928f705fdeb873a@google.com/ Reported-by: syzbot+14234ccf6d0ef629ec1a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000c047db05fdeb8790@google.com/ Reported-by: syzbot+4e2e47f32607d0f72d43@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000bcca3205fdeb87fb@google.com/ Reported-by: syzbot+472626bb5e7c59fb768f@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b55d8805fdeb8385@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reported-and-tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/427646.1686913832@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-16 12:10:32 +01:00
crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE) If an AF_ALG socket bound to a hashing algorithm is sent a zero-length message with MSG_MORE set and then recvmsg() is called without first sending another message without MSG_MORE set to end the operation, an oops will occur because the crypto context and result doesn't now get set up in advance because hash_sendmsg() now defers that as long as possible in the hope that it can use crypto_ahash_digest() - and then because the message is zero-length, it the data wrangling loop is skipped. Fix this by handling zero-length sends at the top of the hash_sendmsg() function. If we're not continuing the previous sendmsg(), then just ignore the send (hash_recvmsg() will invent something when called); if we are continuing, then we finalise the request at this point if MSG_MORE is not set to get any error here, otherwise the send is of no effect and can be ignored. Whilst we're at it, remove the code to create a kvmalloc'd scatterlist if we get more than ALG_MAX_PAGES - this shouldn't happen. Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES") Reported-by: syzbot+13a08c0bf4d212766c3c@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b928f705fdeb873a@google.com/ Reported-by: syzbot+14234ccf6d0ef629ec1a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000c047db05fdeb8790@google.com/ Reported-by: syzbot+4e2e47f32607d0f72d43@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000bcca3205fdeb87fb@google.com/ Reported-by: syzbot+472626bb5e7c59fb768f@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b55d8805fdeb8385@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reported-and-tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/427646.1686913832@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-16 12:10:32 +01:00
crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE) If an AF_ALG socket bound to a hashing algorithm is sent a zero-length message with MSG_MORE set and then recvmsg() is called without first sending another message without MSG_MORE set to end the operation, an oops will occur because the crypto context and result doesn't now get set up in advance because hash_sendmsg() now defers that as long as possible in the hope that it can use crypto_ahash_digest() - and then because the message is zero-length, it the data wrangling loop is skipped. Fix this by handling zero-length sends at the top of the hash_sendmsg() function. If we're not continuing the previous sendmsg(), then just ignore the send (hash_recvmsg() will invent something when called); if we are continuing, then we finalise the request at this point if MSG_MORE is not set to get any error here, otherwise the send is of no effect and can be ignored. Whilst we're at it, remove the code to create a kvmalloc'd scatterlist if we get more than ALG_MAX_PAGES - this shouldn't happen. Fixes: c662b043cdca ("crypto: af_alg/hash: Support MSG_SPLICE_PAGES") Reported-by: syzbot+13a08c0bf4d212766c3c@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b928f705fdeb873a@google.com/ Reported-by: syzbot+14234ccf6d0ef629ec1a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000c047db05fdeb8790@google.com/ Reported-by: syzbot+4e2e47f32607d0f72d43@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000bcca3205fdeb87fb@google.com/ Reported-by: syzbot+472626bb5e7c59fb768f@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000b55d8805fdeb8385@google.com/ Signed-off-by: David Howells <dhowells@redhat.com> Reported-and-tested-by: syzbot+6efc50cc1f8d718d6cb7@syzkaller.appspotmail.com cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/427646.1686913832@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-16 12:10:32 +01:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: af_alg - zero initialize memory allocated via sock_kmalloc Several crypto user API contexts and requests allocated with sock_kmalloc() were left uninitialized, relying on callers to set fields explicitly. This resulted in the use of uninitialized data in certain error paths or when new fields are added in the future. The ACVP patches also contain two user-space interface files: algif_kpp.c and algif_akcipher.c. These too rely on proper initialization of their context structures. A particular issue has been observed with the newly added 'inflight' variable introduced in af_alg_ctx by commit: 67b164a871af ("crypto: af_alg - Disallow multiple in-flight AIO requests") Because the context is not memset to zero after allocation, the inflight variable has contained garbage values. As a result, af_alg_alloc_areq() has incorrectly returned -EBUSY randomly when the garbage value was interpreted as true: https://github.com/gregkh/linux/blame/master/crypto/af_alg.c#L1209 The check directly tests ctx->inflight without explicitly comparing against true/false. Since inflight is only ever set to true or false later, an uninitialized value has triggered -EBUSY failures. Zero-initializing memory allocated with sock_kmalloc() ensures inflight and other fields start in a known state, removing random issues caused by uninitialized data. Fixes: fe869cdb89c9 ("crypto: algif_hash - User-space interface for hash operations") Fixes: 5afdfd22e6ba ("crypto: algif_rng - add random number generator support") Fixes: 2d97591ef43d ("crypto: af_alg - consolidation of duplicate code") Fixes: 67b164a871af ("crypto: af_alg - Disallow multiple in-flight AIO requests") Cc: stable@vger.kernel.org Signed-off-by: Shivani Agarwal <shivani.agarwal@broadcom.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-09-23 23:01:48 -07:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00
crypto: hash - prevent using keyed hashes without setting key Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot <syzkaller@googlegroups.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-01-03 11:16:27 -08:00