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2017-11-02Merge tag 'spdx_identifiers-4.14-rc8' of ↵Linus Torvalds4-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull initial SPDX identifiers from Greg KH: "License cleanup: add SPDX license identifiers to some files Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: License cleanup: add SPDX license identifier to uapi header files with a license License cleanup: add SPDX license identifier to uapi header files with no license License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman4-0/+4
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02KEYS: trusted: fix writing past end of buffer in trusted_read()Eric Biggers1-11/+12
When calling keyctl_read() on a key of type "trusted", if the user-supplied buffer was too small, the kernel ignored the buffer length and just wrote past the end of the buffer, potentially corrupting userspace memory. Fix it by instead returning the size required, as per the documentation for keyctl_read(). We also don't even fill the buffer at all in this case, as this is slightly easier to implement than doing a short read, and either behavior appears to be permitted. It also makes it match the behavior of the "encrypted" key type. Fixes: d00a1c72f7f4 ("keys: add new trusted key-type") Reported-by: Ben Hutchings <ben@decadent.org.uk> Cc: <stable@vger.kernel.org> # v2.6.38+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-11-02KEYS: return full count in keyring_read() if buffer is too smallEric Biggers1-20/+19
Commit e645016abc80 ("KEYS: fix writing past end of user-supplied buffer in keyring_read()") made keyring_read() stop corrupting userspace memory when the user-supplied buffer is too small. However it also made the return value in that case be the short buffer size rather than the size required, yet keyctl_read() is actually documented to return the size required. Therefore, switch it over to the documented behavior. Note that for now we continue to have it fill the short buffer, since it did that before (pre-v3.13) and dump_key_tree_aux() in keyutils arguably relies on it. Fixes: e645016abc80 ("KEYS: fix writing past end of user-supplied buffer in keyring_read()") Reported-by: Ben Hutchings <ben@decadent.org.uk> Cc: <stable@vger.kernel.org> # v3.13+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-18KEYS: load key flags and expiry time atomically in proc_keys_show()Eric Biggers1-10/+14
In proc_keys_show(), the key semaphore is not held, so the key ->flags and ->expiry can be changed concurrently. We therefore should read them atomically just once. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18KEYS: Load key expiry time atomically in keyring_search_iterator()Eric Biggers1-1/+3
Similar to the case for key_validate(), we should load the key ->expiry once atomically in keyring_search_iterator(), since it can be changed concurrently with the flags whenever the key semaphore isn't held. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18KEYS: load key flags and expiry time atomically in key_validate()Eric Biggers1-3/+4
In key_validate(), load the flags and expiry time once atomically, since these can change concurrently if key_validate() is called without the key semaphore held. And we don't want to get inconsistent results if a variable is referenced multiple times. For example, key->expiry was referenced in both 'if (key->expiry)' and in 'if (now.tv_sec >= key->expiry)', making it theoretically possible to see a spurious EKEYEXPIRED while the expiration time was being removed, i.e. set to 0. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18KEYS: don't let add_key() update an uninstantiated keyDavid Howells1-0/+10
Currently, when passed a key that already exists, add_key() will call the key's ->update() method if such exists. But this is heavily broken in the case where the key is uninstantiated because it doesn't call __key_instantiate_and_link(). Consequently, it doesn't do most of the things that are supposed to happen when the key is instantiated, such as setting the instantiation state, clearing KEY_FLAG_USER_CONSTRUCT and awakening tasks waiting on it, and incrementing key->user->nikeys. It also never takes key_construction_mutex, which means that ->instantiate() can run concurrently with ->update() on the same key. In the case of the "user" and "logon" key types this causes a memory leak, at best. Maybe even worse, the ->update() methods of the "encrypted" and "trusted" key types actually just dereference a NULL pointer when passed an uninstantiated key. Change key_create_or_update() to wait interruptibly for the key to finish construction before continuing. This patch only affects *uninstantiated* keys. For now we still allow a negatively instantiated key to be updated (thereby positively instantiating it), although that's broken too (the next patch fixes it) and I'm not sure that anyone actually uses that functionality either. Here is a simple reproducer for the bug using the "encrypted" key type (requires CONFIG_ENCRYPTED_KEYS=y), though as noted above the bug pertained to more than just the "encrypted" key type: #include <stdlib.h> #include <unistd.h> #include <keyutils.h> int main(void) { int ringid = keyctl_join_session_keyring(NULL); if (fork()) { for (;;) { const char payload[] = "update user:foo 32"; usleep(rand() % 10000); add_key("encrypted", "desc", payload, sizeof(payload), ringid); keyctl_clear(ringid); } } else { for (;;) request_key("encrypted", "desc", "callout_info", ringid); } } It causes: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: encrypted_update+0xb0/0x170 PGD 7a178067 P4D 7a178067 PUD 77269067 PMD 0 PREEMPT SMP CPU: 0 PID: 340 Comm: reproduce Tainted: G D 4.14.0-rc1-00025-g428490e38b2e #796 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff8a467a39a340 task.stack: ffffb15c40770000 RIP: 0010:encrypted_update+0xb0/0x170 RSP: 0018:ffffb15c40773de8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8a467a275b00 RCX: 0000000000000000 RDX: 0000000000000005 RSI: ffff8a467a275b14 RDI: ffffffffb742f303 RBP: ffffb15c40773e20 R08: 0000000000000000 R09: ffff8a467a275b17 R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8a4677057180 R15: ffff8a467a275b0f FS: 00007f5d7fb08700(0000) GS:ffff8a467f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 0000000077262005 CR4: 00000000001606f0 Call Trace: key_create_or_update+0x2bc/0x460 SyS_add_key+0x10c/0x1d0 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7f5d7f211259 RSP: 002b:00007ffed03904c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8 RAX: ffffffffffffffda RBX: 000000003b2a7955 RCX: 00007f5d7f211259 RDX: 00000000004009e4 RSI: 00000000004009ff RDI: 0000000000400a04 RBP: 0000000068db8bad R08: 000000003b2a7955 R09: 0000000000000004 R10: 000000000000001a R11: 0000000000000246 R12: 0000000000400868 R13: 00007ffed03905d0 R14: 0000000000000000 R15: 0000000000000000 Code: 77 28 e8 64 34 1f 00 45 31 c0 31 c9 48 8d 55 c8 48 89 df 48 8d 75 d0 e8 ff f9 ff ff 85 c0 41 89 c4 0f 88 84 00 00 00 4c 8b 7d c8 <49> 8b 75 18 4c 89 ff e8 24 f8 ff ff 85 c0 41 89 c4 78 6d 49 8b RIP: encrypted_update+0xb0/0x170 RSP: ffffb15c40773de8 CR2: 0000000000000018 Cc: <stable@vger.kernel.org> # v2.6.12+ Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Eric Biggers <ebiggers@google.com>
2017-10-18KEYS: Fix race between updating and finding a negative keyDavid Howells12-39/+49
Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection error into one field such that: (1) The instantiation state can be modified/read atomically. (2) The error can be accessed atomically with the state. (3) The error isn't stored unioned with the payload pointers. This deals with the problem that the state is spread over three different objects (two bits and a separate variable) and reading or updating them atomically isn't practical, given that not only can uninstantiated keys change into instantiated or rejected keys, but rejected keys can also turn into instantiated keys - and someone accessing the key might not be using any locking. The main side effect of this problem is that what was held in the payload may change, depending on the state. For instance, you might observe the key to be in the rejected state. You then read the cached error, but if the key semaphore wasn't locked, the key might've become instantiated between the two reads - and you might now have something in hand that isn't actually an error code. The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error code if the key is negatively instantiated. The key_is_instantiated() function is replaced with key_is_positive() to avoid confusion as negative keys are also 'instantiated'. Additionally, barriering is included: (1) Order payload-set before state-set during instantiation. (2) Order state-read before payload-read when using the key. Further separate barriering is necessary if RCU is being used to access the payload content after reading the payload pointers. Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data") Cc: stable@vger.kernel.org # v4.4+ Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Eric Biggers <ebiggers@google.com>
2017-10-18security/keys: BIG_KEY requires CONFIG_CRYPTOArnd Bergmann1-0/+1
The recent rework introduced a possible randconfig build failure when CONFIG_CRYPTO configured to only allow modules: security/keys/big_key.o: In function `big_key_crypt': big_key.c:(.text+0x29f): undefined reference to `crypto_aead_setkey' security/keys/big_key.o: In function `big_key_init': big_key.c:(.init.text+0x1a): undefined reference to `crypto_alloc_aead' big_key.c:(.init.text+0x45): undefined reference to `crypto_aead_setauthsize' big_key.c:(.init.text+0x77): undefined reference to `crypto_destroy_tfm' crypto/gcm.o: In function `gcm_hash_crypt_remain_continue': gcm.c:(.text+0x167): undefined reference to `crypto_ahash_finup' crypto/gcm.o: In function `crypto_gcm_exit_tfm': gcm.c:(.text+0x847): undefined reference to `crypto_destroy_tfm' When we 'select CRYPTO' like the other users, we always get a configuration that builds. Fixes: 428490e38b2e ("security/keys: rewrite all of big_key crypto") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-12KEYS: encrypted: fix dereference of NULL user_key_payloadEric Biggers1-0/+7
A key of type "encrypted" references a "master key" which is used to encrypt and decrypt the encrypted key's payload. However, when we accessed the master key's payload, we failed to handle the case where the master key has been revoked, which sets the payload pointer to NULL. Note that request_key() *does* skip revoked keys, but there is still a window where the key can be revoked before we acquire its semaphore. Fix it by checking for a NULL payload, treating it like a key which was already revoked at the time it was requested. This was an issue for master keys of type "user" only. Master keys can also be of type "trusted", but those cannot be revoked. Fixes: 7e70cb497850 ("keys: add new key-type encrypted") Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: <stable@vger.kernel.org> [v2.6.38+] Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-26security/keys: rewrite all of big_key cryptoJason A. Donenfeld2-71/+60
This started out as just replacing the use of crypto/rng with get_random_bytes_wait, so that we wouldn't use bad randomness at boot time. But, upon looking further, it appears that there were even deeper underlying cryptographic problems, and that this seems to have been committed with very little crypto review. So, I rewrote the whole thing, trying to keep to the conventions introduced by the previous author, to fix these cryptographic flaws. It makes no sense to seed crypto/rng at boot time and then keep using it like this, when in fact there's already get_random_bytes_wait, which can ensure there's enough entropy and be a much more standard way of generating keys. Since this sensitive material is being stored untrusted, using ECB and no authentication is simply not okay at all. I find it surprising and a bit horrifying that this code even made it past basic crypto review, which perhaps points to some larger issues. This patch moves from using AES-ECB to using AES-GCM. Since keys are uniquely generated each time, we can set the nonce to zero. There was also a race condition in which the same key would be reused at the same time in different threads. A mutex fixes this issue now. So, to summarize, this commit fixes the following vulnerabilities: * Low entropy key generation, allowing an attacker to potentially guess or predict keys. * Unauthenticated encryption, allowing an attacker to modify the cipher text in particular ways in order to manipulate the plaintext, which is is even more frightening considering the next point. * Use of ECB mode, allowing an attacker to trivially swap blocks or compare identical plaintext blocks. * Key re-use. * Faulty memory zeroing. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kirill Marinushkin <k.marinushkin@gmail.com> Cc: security@kernel.org Cc: stable@vger.kernel.org
2017-09-26security/keys: properly zero out sensitive key material in big_keyJason A. Donenfeld1-6/+6
Error paths forgot to zero out sensitive material, so this patch changes some kfrees into a kzfrees. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Eric Biggers <ebiggers3@gmail.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kirill Marinushkin <k.marinushkin@gmail.com> Cc: security@kernel.org Cc: stable@vger.kernel.org
2017-09-25KEYS: use kmemdup() in request_key_auth_new()Eric Biggers1-3/+2
kmemdup() is preferred to kmalloc() followed by memcpy(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: restrict /proc/keys by credentials at open timeEric Biggers1-6/+2
When checking for permission to view keys whilst reading from /proc/keys, we should use the credentials with which the /proc/keys file was opened. This is because, in a classic type of exploit, it can be possible to bypass checks for the *current* credentials by passing the file descriptor to a suid program. Following commit 34dbbcdbf633 ("Make file credentials available to the seqfile interfaces") we can finally fix it. So let's do it. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: reset parent each time before searching key_user_treeEric Biggers1-2/+2
In key_user_lookup(), if there is no key_user for the given uid, we drop key_user_lock, allocate a new key_user, and search the tree again. But we failed to set 'parent' to NULL at the beginning of the second search. If the tree were to be empty for the second search, the insertion would be done with an invalid 'parent', scribbling over freed memory. Fortunately this can't actually happen currently because the tree always contains at least the root_key_user. But it still should be fixed to make the code more robust. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: prevent KEYCTL_READ on negative keyEric Biggers1-0/+5
Because keyctl_read_key() looks up the key with no permissions requested, it may find a negatively instantiated key. If the key is also possessed, we went ahead and called ->read() on the key. But the key payload will actually contain the ->reject_error rather than the normal payload. Thus, the kernel oopses trying to read the user_key_payload from memory address (int)-ENOKEY = 0x00000000ffffff82. Fortunately the payload data is stored inline, so it shouldn't be possible to abuse this as an arbitrary memory read primitive... Reproducer: keyctl new_session keyctl request2 user desc '' @s keyctl read $(keyctl show | awk '/user: desc/ {print $1}') It causes a crash like the following: BUG: unable to handle kernel paging request at 00000000ffffff92 IP: user_read+0x33/0xa0 PGD 36a54067 P4D 36a54067 PUD 0 Oops: 0000 [#1] SMP CPU: 0 PID: 211 Comm: keyctl Not tainted 4.14.0-rc1 #337 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 task: ffff90aa3b74c3c0 task.stack: ffff9878c0478000 RIP: 0010:user_read+0x33/0xa0 RSP: 0018:ffff9878c047bee8 EFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff90aa3d7da340 RCX: 0000000000000017 RDX: 0000000000000000 RSI: 00000000ffffff82 RDI: ffff90aa3d7da340 RBP: ffff9878c047bf00 R08: 00000024f95da94f R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f58ece69740(0000) GS:ffff90aa3e200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000ffffff92 CR3: 0000000036adc001 CR4: 00000000003606f0 Call Trace: keyctl_read_key+0xac/0xe0 SyS_keyctl+0x99/0x120 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7f58ec787bb9 RSP: 002b:00007ffc8d401678 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa RAX: ffffffffffffffda RBX: 00007ffc8d402800 RCX: 00007f58ec787bb9 RDX: 0000000000000000 RSI: 00000000174a63ac RDI: 000000000000000b RBP: 0000000000000004 R08: 00007ffc8d402809 R09: 0000000000000020 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffc8d402800 R13: 00007ffc8d4016e0 R14: 0000000000000000 R15: 0000000000000000 Code: e5 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb e8 a4 b4 ad ff 85 c0 74 09 80 3d b9 4c 96 00 00 74 43 48 8b b3 20 01 00 00 4d 85 ed <0f> b7 5e 10 74 29 4d 85 e4 74 24 4c 39 e3 4c 89 e2 4c 89 ef 48 RIP: user_read+0x33/0xa0 RSP: ffff9878c047bee8 CR2: 00000000ffffff92 Fixes: 61ea0c0ba904 ("KEYS: Skip key state checks when checking for possession") Cc: <stable@vger.kernel.org> [v3.13+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: prevent creating a different user's keyringsEric Biggers4-12/+21
It was possible for an unprivileged user to create the user and user session keyrings for another user. For example: sudo -u '#3000' sh -c 'keyctl add keyring _uid.4000 "" @u keyctl add keyring _uid_ses.4000 "" @u sleep 15' & sleep 1 sudo -u '#4000' keyctl describe @u sudo -u '#4000' keyctl describe @us This is problematic because these "fake" keyrings won't have the right permissions. In particular, the user who created them first will own them and will have full access to them via the possessor permissions, which can be used to compromise the security of a user's keys: -4: alswrv-----v------------ 3000 0 keyring: _uid.4000 -5: alswrv-----v------------ 3000 0 keyring: _uid_ses.4000 Fix it by marking user and user session keyrings with a flag KEY_FLAG_UID_KEYRING. Then, when searching for a user or user session keyring by name, skip all keyrings that don't have the flag set. Fixes: 69664cf16af4 ("keys: don't generate user and user session keyrings unless they're accessed") Cc: <stable@vger.kernel.org> [v2.6.26+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix writing past end of user-supplied buffer in keyring_read()Eric Biggers1-9/+5
Userspace can call keyctl_read() on a keyring to get the list of IDs of keys in the keyring. But if the user-supplied buffer is too small, the kernel would write the full list anyway --- which will corrupt whatever userspace memory happened to be past the end of the buffer. Fix it by only filling the space that is available. Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring") Cc: <stable@vger.kernel.org> [v3.13+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix key refcount leak in keyctl_read_key()Eric Biggers1-1/+1
In keyctl_read_key(), if key_permission() were to return an error code other than EACCES, we would leak a the reference to the key. This can't actually happen currently because key_permission() can only return an error code other than EACCES if security_key_permission() does, only SELinux and Smack implement that hook, and neither can return an error code other than EACCES. But it should still be fixed, as it is a bug waiting to happen. Fixes: 29db91906340 ("[PATCH] Keys: Add LSM hooks for key management [try #3]") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix key refcount leak in keyctl_assume_authority()Eric Biggers1-4/+2
In keyctl_assume_authority(), if keyctl_change_reqkey_auth() were to fail, we would leak the reference to the 'authkey'. Currently this can only happen if prepare_creds() fails to allocate memory. But it still should be fixed, as it is a more severe bug waiting to happen. This patch also moves the read of 'authkey->serial' to before the reference to the authkey is dropped. Doing the read after dropping the reference is very fragile because it assumes we still hold another reference to the key. (Which we do, in current->cred->request_key_auth, but there's no reason not to write it in the "obviously correct" way.) Fixes: d84f4f992cbd ("CRED: Inaugurate COW credentials") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: don't revoke uninstantiated key in request_key_auth_new()Eric Biggers1-1/+0
If key_instantiate_and_link() were to fail (which fortunately isn't possible currently), the call to key_revoke(authkey) would crash with a NULL pointer dereference in request_key_auth_revoke() because the key has not yet been instantiated. Fix this by removing the call to key_revoke(). key_put() is sufficient, as it's not possible for an uninstantiated authkey to have been used for anything yet. Fixes: b5f545c880a2 ("[PATCH] keys: Permit running process to instantiate keys") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-25KEYS: fix cred refcount leak in request_key_auth_new()Eric Biggers1-37/+31
In request_key_auth_new(), if key_alloc() or key_instantiate_and_link() were to fail, we would leak a reference to the 'struct cred'. Currently this can only happen if key_alloc() fails to allocate memory. But it still should be fixed, as it is a more severe bug waiting to happen. Fix it by cleaning things up to use a helper function which frees a 'struct request_key_auth' correctly. Fixes: d84f4f992cbd ("CRED: Inaugurate COW credentials") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-09-05fs: fix kernel_write prototypeChristoph Hellwig1-1/+2
Make the position an in/out argument like all the other read/write helpers and and make the buf argument a void pointer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-05fs: fix kernel_read prototypeChristoph Hellwig1-1/+2
Use proper ssize_t and size_t types for the return value and count argument, move the offset last and make it an in/out argument like all other read/write helpers, and make the buf argument a void pointer to get rid of lots of casts in the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-19Merge tag 'gcc-plugins-v4.13-rc2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull structure randomization updates from Kees Cook: "Now that IPC and other changes have landed, enable manual markings for randstruct plugin, including the task_struct. This is the rest of what was staged in -next for the gcc-plugins, and comes in three patches, largest first: - mark "easy" structs with __randomize_layout - mark task_struct with an optional anonymous struct to isolate the __randomize_layout section - mark structs to opt _out_ of automated marking (which will come later) And, FWIW, this continues to pass allmodconfig (normal and patched to enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and s390 for me" * tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randstruct: opt-out externally exposed function pointer structs task_struct: Allow randomized layout randstruct: Mark various structs for randomization
2017-07-14KEYS: DH: validate __spare fieldEric Biggers2-0/+7
Syscalls must validate that their reserved arguments are zero and return EINVAL otherwise. Otherwise, it will be impossible to actually use them for anything in the future because existing programs may be passing garbage in. This is standard practice when adding new APIs. Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-07-04Merge tag 'docs-4.13' of git://git.lwn.net/linuxLinus Torvalds5-5/+5
Pull documentation updates from Jonathan Corbet: "There has been a fair amount of activity in the docs tree this time around. Highlights include: - Conversion of a bunch of security documentation into RST - The conversion of the remaining DocBook templates by The Amazing Mauro Machine. We can now drop the entire DocBook build chain. - The usual collection of fixes and minor updates" * tag 'docs-4.13' of git://git.lwn.net/linux: (90 commits) scripts/kernel-doc: handle DECLARE_HASHTABLE Documentation: atomic_ops.txt is core-api/atomic_ops.rst Docs: clean up some DocBook loose ends Make the main documentation title less Geocities Docs: Use kernel-figure in vidioc-g-selection.rst Docs: fix table problems in ras.rst Docs: Fix breakage with Sphinx 1.5 and upper Docs: Include the Latex "ifthen" package doc/kokr/howto: Only send regression fixes after -rc1 docs-rst: fix broken links to dynamic-debug-howto in kernel-parameters doc: Document suitability of IBM Verse for kernel development Doc: fix a markup error in coding-style.rst docs: driver-api: i2c: remove some outdated information Documentation: DMA API: fix a typo in a function name Docs: Insert missing space to separate link from text doc/ko_KR/memory-barriers: Update control-dependencies example Documentation, kbuild: fix typo "minimun" -> "minimum" docs: Fix some formatting issues in request-key.rst doc: ReSTify keys-trusted-encrypted.txt doc: ReSTify keys-request-key.txt ...
2017-06-30randstruct: Mark various structs for randomizationKees Cook1-1/+1
This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-06-20sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into ↵Ingo Molnar1-0/+1
<linux/wait_bit.h> The wait_bit*() types and APIs are mixed into wait.h, but they are a pretty orthogonal extension of wait-queues. Furthermore, only about 50 kernel files use these APIs, while over 1000 use the regular wait-queue functionality. So clean up the main wait.h by moving the wait-bit functionality out of it, into a separate .h and .c file: include/linux/wait_bit.h for types and APIs kernel/sched/wait_bit.c for the implementation Update all header dependencies. This reduces the size of wait.h rather significantly, by about 30%. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-09KEYS: fix refcount_inc() on zeroMark Rutland1-7/+4
If a key's refcount is dropped to zero between key_lookup() peeking at the refcount and subsequently attempting to increment it, refcount_inc() will see a zero refcount. Here, refcount_inc() will WARN_ONCE(), and will *not* increment the refcount, which will remain zero. Once key_lookup() drops key_serial_lock, it is possible for the key to be freed behind our back. This patch uses refcount_inc_not_zero() to perform the peek and increment atomically. Fixes: fff292914d3a2f1e ("security, keys: convert key.usage from atomic_t to refcount_t") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: David Howells <dhowells@redhat.com> Cc: David Windsor <dwindsor@gmail.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Hans Liljestrand <ishkamiel@gmail.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP APIMat Martineau2-103/+171
The initial Diffie-Hellman computation made direct use of the MPI library because the crypto module did not support DH at the time. Now that KPP is implemented, KEYCTL_DH_COMPUTE should use it to get rid of duplicate code and leverage possible hardware acceleration. This fixes an issue whereby the input to the KDF computation would include additional uninitialized memory when the result of the Diffie-Hellman computation was shorter than the input prime number. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: DH: ensure the KDF counter is properly alignedEric Biggers1-13/+3
Accessing a 'u8[4]' through a '__be32 *' violates alignment rules. Just make the counter a __be32 instead. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: DH: don't feed uninitialized "otherinfo" into KDFEric Biggers1-1/+1
If userspace called KEYCTL_DH_COMPUTE with kdf_params containing NULL otherinfo but nonzero otherinfolen, the kernel would allocate a buffer for the otherinfo, then feed it into the KDF without initializing it. Fix this by always doing the copy from userspace (which will fail with EFAULT in this scenario). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: DH: forbid using digest_null as the KDF hashEric Biggers1-1/+11
Requesting "digest_null" in the keyctl_kdf_params caused an infinite loop in kdf_ctr() because the "null" hash has a digest size of 0. Fix it by rejecting hash algorithms with a digest size of 0. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: sanitize key structs before freeingEric Biggers1-3/+1
While a 'struct key' itself normally does not contain sensitive information, Documentation/security/keys.txt actually encourages this: "Having a payload is not required; and the payload can, in fact, just be a value stored in the struct key itself." In case someone has taken this advice, or will take this advice in the future, zero the key structure before freeing it. We might as well, and as a bonus this could make it a bit more difficult for an adversary to determine which keys have recently been in use. This is safe because the key_jar cache does not use a constructor. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: trusted: sanitize all key materialEric Biggers1-28/+22
As the previous patch did for encrypted-keys, zero sensitive any potentially sensitive data related to the "trusted" key type before it is freed. Notably, we were not zeroing the tpm_buf structures in which the actual key is stored for TPM seal and unseal, nor were we zeroing the trusted_key_payload in certain error paths. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: encrypted: sanitize all key materialEric Biggers1-18/+13
For keys of type "encrypted", consistently zero sensitive key material before freeing it. This was already being done for the decrypted payloads of encrypted keys, but not for the master key and the keys derived from the master key. Out of an abundance of caution and because it is trivial to do so, also zero buffers containing the key payload in encrypted form, although depending on how the encrypted-keys feature is used such information does not necessarily need to be kept secret. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Safford <safford@us.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: user_defined: sanitize key payloadsEric Biggers1-4/+12
Zero the payloads of user and logon keys before freeing them. This prevents sensitive key material from being kept around in the slab caches after a key is released. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: sanitize add_key() and keyctl() key payloadsEric Biggers1-3/+9
Before returning from add_key() or one of the keyctl() commands that takes in a key payload, zero the temporary buffer that was allocated to hold the key payload copied from userspace. This may contain sensitive key material that should not be kept around in the slab caches. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: fix freeing uninitialized memory in key_update()Eric Biggers1-3/+2
key_update() freed the key_preparsed_payload even if it was not initialized first. This would cause a crash if userspace called keyctl_update() on a key with type like "asymmetric" that has a ->preparse() method but not an ->update() method. Possibly it could even be triggered for other key types by racing with keyctl_setperm() to make the KEY_NEED_WRITE check fail (the permission was already checked, so normally it wouldn't fail there). Reproducer with key type "asymmetric", given a valid cert.der: keyctl new_session keyid=$(keyctl padd asymmetric desc @s < cert.der) keyctl setperm $keyid 0x3f000000 keyctl update $keyid data [ 150.686666] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001 [ 150.687601] IP: asymmetric_key_free_kids+0x12/0x30 [ 150.688139] PGD 38a3d067 [ 150.688141] PUD 3b3de067 [ 150.688447] PMD 0 [ 150.688745] [ 150.689160] Oops: 0000 [#1] SMP [ 150.689455] Modules linked in: [ 150.689769] CPU: 1 PID: 2478 Comm: keyctl Not tainted 4.11.0-rc4-xfstests-00187-ga9f6b6b8cd2f #742 [ 150.690916] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 [ 150.692199] task: ffff88003b30c480 task.stack: ffffc90000350000 [ 150.692952] RIP: 0010:asymmetric_key_free_kids+0x12/0x30 [ 150.693556] RSP: 0018:ffffc90000353e58 EFLAGS: 00010202 [ 150.694142] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000004 [ 150.694845] RDX: ffffffff81ee3920 RSI: ffff88003d4b0700 RDI: 0000000000000001 [ 150.697569] RBP: ffffc90000353e60 R08: ffff88003d5d2140 R09: 0000000000000000 [ 150.702483] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 [ 150.707393] R13: 0000000000000004 R14: ffff880038a4d2d8 R15: 000000000040411f [ 150.709720] FS: 00007fcbcee35700(0000) GS:ffff88003fd00000(0000) knlGS:0000000000000000 [ 150.711504] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 150.712733] CR2: 0000000000000001 CR3: 0000000039eab000 CR4: 00000000003406e0 [ 150.714487] Call Trace: [ 150.714975] asymmetric_key_free_preparse+0x2f/0x40 [ 150.715907] key_update+0xf7/0x140 [ 150.716560] ? key_default_cmp+0x20/0x20 [ 150.717319] keyctl_update_key+0xb0/0xe0 [ 150.718066] SyS_keyctl+0x109/0x130 [ 150.718663] entry_SYSCALL_64_fastpath+0x1f/0xc2 [ 150.719440] RIP: 0033:0x7fcbce75ff19 [ 150.719926] RSP: 002b:00007ffd5d167088 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa [ 150.720918] RAX: ffffffffffffffda RBX: 0000000000404d80 RCX: 00007fcbce75ff19 [ 150.721874] RDX: 00007ffd5d16785e RSI: 000000002866cd36 RDI: 0000000000000002 [ 150.722827] RBP: 0000000000000006 R08: 000000002866cd36 R09: 00007ffd5d16785e [ 150.723781] R10: 0000000000000004 R11: 0000000000000206 R12: 0000000000404d80 [ 150.724650] R13: 00007ffd5d16784d R14: 00007ffd5d167238 R15: 000000000040411f [ 150.725447] Code: 83 c4 08 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 85 ff 74 23 55 48 89 e5 53 48 89 fb <48> 8b 3f e8 06 21 c5 ff 48 8b 7b 08 e8 fd 20 c5 ff 48 89 df e8 [ 150.727489] RIP: asymmetric_key_free_kids+0x12/0x30 RSP: ffffc90000353e58 [ 150.728117] CR2: 0000000000000001 [ 150.728430] ---[ end trace f7f8fe1da2d5ae8d ]--- Fixes: 4d8c0250b841 ("KEYS: Call ->free_preparse() even after ->preparse() returns an error") Cc: stable@vger.kernel.org # 3.17+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: fix dereferencing NULL payload with nonzero lengthEric Biggers1-2/+2
sys_add_key() and the KEYCTL_UPDATE operation of sys_keyctl() allowed a NULL payload with nonzero length to be passed to the key type's ->preparse(), ->instantiate(), and/or ->update() methods. Various key types including asymmetric, cifs.idmap, cifs.spnego, and pkcs7_test did not handle this case, allowing an unprivileged user to trivially cause a NULL pointer dereference (kernel oops) if one of these key types was present. Fix it by doing the copy_from_user() when 'plen' is nonzero rather than when '_payload' is non-NULL, causing the syscall to fail with EFAULT as expected when an invalid buffer is specified. Cc: stable@vger.kernel.org # 2.6.10+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: encrypted: use constant-time HMAC comparisonEric Biggers1-2/+3
MACs should, in general, be compared using crypto_memneq() to prevent timing attacks. Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: encrypted: fix race causing incorrect HMAC calculationsEric Biggers1-83/+32
The encrypted-keys module was using a single global HMAC transform, which could be rekeyed by multiple threads concurrently operating on different keys, causing incorrect HMAC values to be calculated. Fix this by allocating a new HMAC transform whenever we need to calculate a HMAC. Also simplify things a bit by allocating the shash_desc's using SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes. The following script reproduces the bug: keyctl new_session keyctl add user master "abcdefghijklmnop" @s for i in $(seq 2); do ( set -e for j in $(seq 1000); do keyid=$(keyctl add encrypted desc$i "new user:master 25" @s) datablob="$(keyctl pipe $keyid)" keyctl unlink $keyid > /dev/null keyid=$(keyctl add encrypted desc$i "load $datablob" @s) keyctl unlink $keyid > /dev/null done ) & done Output with bug: [ 439.691094] encrypted_key: bad hmac (-22) add_key: Invalid argument add_key: Invalid argument Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: encrypted: fix buffer overread in valid_master_desc()Eric Biggers1-16/+15
With the 'encrypted' key type it was possible for userspace to provide a data blob ending with a master key description shorter than expected, e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a master key description, validate_master_desc() could read beyond the end of the buffer. Fix this by using strncmp() instead of memcmp(). [Also clean up the code to deduplicate some logic.] Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: encrypted: avoid encrypting/decrypting stack buffersEric Biggers1-8/+9
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt stack buffers because the stack may be virtually mapped. Fix this for the padding buffers in encrypted-keys by using ZERO_PAGE for the encryption padding and by allocating a temporary heap buffer for the decryption padding. Tested with CONFIG_DEBUG_SG=y: keyctl new_session keyctl add user master "abcdefghijklmnop" @s keyid=$(keyctl add encrypted desc "new user:master 25" @s) datablob="$(keyctl pipe $keyid)" keyctl unlink $keyid keyid=$(keyctl add encrypted desc "load $datablob" @s) datablob2="$(keyctl pipe $keyid)" [ "$datablob" = "$datablob2" ] && echo "Success!" Cc: Andy Lutomirski <luto@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: put keyring if install_session_keyring_to_cred() failsEric Biggers1-3/+4
In join_session_keyring(), if install_session_keyring_to_cred() were to fail, we would leak the keyring reference, just like in the bug fixed by commit 23567fd052a9 ("KEYS: Fix keyring ref leak in join_session_keyring()"). Fortunately this cannot happen currently, but we really should be more careful. Do this by adding and using a new error label at which the keyring reference is dropped. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09KEYS: Delete an error message for a failed memory allocation in ↵Markus Elfring1-3/+2
get_derived_key() Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09security: use READ_ONCE instead of deprecated ACCESS_ONCEDavidlohr Bueso1-6/+6
With the new standardized functions, we can replace all ACCESS_ONCE() calls across relevant security/keyrings/. ACCESS_ONCE() does not work reliably on non-scalar types. For example gcc 4.6 and 4.7 might remove the volatile tag for such accesses during the SRA (scalar replacement of aggregates) step: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 Update the new calls regardless of if it is a scalar type, this is cleaner than having three alternatives. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09security/keys: add CONFIG_KEYS_COMPAT to KconfigBilal Amarni1-0/+4
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for several 64-bit architectures : mips, parisc, tile. At the moment and for those architectures, calling in 32-bit userspace the keyctl syscall would return an ENOSYS error. This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to make sure the compatibility wrapper is registered by default for any 64-bit architecture as long as it is configured with CONFIG_COMPAT. [DH: Modified to remove arm64 compat enablement also as requested by Eric Biggers] Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> cc: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: James Morris <james.l.morris@oracle.com>