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2014-10-29Merge branch 'for-linus' of ↵James Morris
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into for-linus
2014-10-28ima: check xattr value length and type in the ima_inode_setxattr()Dmitry Kasatkin
ima_inode_setxattr() can be called with no value. Function does not check the length so that following command can be used to produce kernel oops: setfattr -n security.ima FOO. This patch fixes it. Changes in v3: * for stable reverted "allow setting hash only in fix or log mode" It will be a separate patch. Changes in v2: * testing validity of xattr type * allow setting hash only in fix or log mode (Mimi) [ 261.562522] BUG: unable to handle kernel NULL pointer dereference at (null) [ 261.564109] IP: [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a [ 261.564109] PGD 3112f067 PUD 42965067 PMD 0 [ 261.564109] Oops: 0000 [#1] SMP [ 261.564109] Modules linked in: bridge stp llc evdev serio_raw i2c_piix4 button fuse [ 261.564109] CPU: 0 PID: 3299 Comm: setxattr Not tainted 3.16.0-kds+ #2924 [ 261.564109] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 261.564109] task: ffff8800428c2430 ti: ffff880042be0000 task.ti: ffff880042be0000 [ 261.564109] RIP: 0010:[<ffffffff812af272>] [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a [ 261.564109] RSP: 0018:ffff880042be3d50 EFLAGS: 00010246 [ 261.564109] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000015 [ 261.564109] RDX: 0000001500000000 RSI: 0000000000000000 RDI: ffff8800375cc600 [ 261.564109] RBP: ffff880042be3d68 R08: 0000000000000000 R09: 00000000004d6256 [ 261.564109] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88002149ba00 [ 261.564109] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 261.564109] FS: 00007f6c1e219740(0000) GS:ffff88005da00000(0000) knlGS:0000000000000000 [ 261.564109] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 261.564109] CR2: 0000000000000000 CR3: 000000003b35a000 CR4: 00000000000006f0 [ 261.564109] Stack: [ 261.564109] ffff88002149ba00 ffff880042be3df8 0000000000000000 ffff880042be3d98 [ 261.564109] ffffffff812a101b ffff88002149ba00 ffff880042be3df8 0000000000000000 [ 261.564109] 0000000000000000 ffff880042be3de0 ffffffff8116d08a ffff880042be3dc8 [ 261.564109] Call Trace: [ 261.564109] [<ffffffff812a101b>] security_inode_setxattr+0x48/0x6a [ 261.564109] [<ffffffff8116d08a>] vfs_setxattr+0x6b/0x9f [ 261.564109] [<ffffffff8116d1e0>] setxattr+0x122/0x16c [ 261.564109] [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45 [ 261.564109] [<ffffffff8114d011>] ? __sb_start_write+0x10f/0x143 [ 261.564109] [<ffffffff811687e8>] ? mnt_want_write+0x21/0x45 [ 261.564109] [<ffffffff811687c0>] ? __mnt_want_write+0x48/0x4f [ 261.564109] [<ffffffff8116d3e6>] SyS_setxattr+0x6e/0xb0 [ 261.564109] [<ffffffff81529da9>] system_call_fastpath+0x16/0x1b [ 261.564109] Code: 48 89 f7 48 c7 c6 58 36 81 81 53 31 db e8 73 27 04 00 85 c0 75 28 bf 15 00 00 00 e8 8a a5 d9 ff 84 c0 75 05 83 cb ff eb 15 31 f6 <41> 80 7d 00 03 49 8b 7c 24 68 40 0f 94 c6 e8 e1 f9 ff ff 89 d8 [ 261.564109] RIP [<ffffffff812af272>] ima_inode_setxattr+0x3e/0x5a [ 261.564109] RSP <ffff880042be3d50> [ 261.564109] CR2: 0000000000000000 [ 261.599998] ---[ end trace 39a89a3fc267e652 ]--- Reported-by: Jan Kara <jack@suse.cz> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-10-14security, crypto: LLVMLinux: Remove VLAIS from ima_crypto.cBehan Webster
Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99 compliant equivalent. This patch allocates the appropriate amount of memory using a char array using the SHASH_DESC_ON_STACK macro. The new code can be compiled with both gcc and clang. Signed-off-by: Behan Webster <behanw@converseincode.com> Reviewed-by: Mark Charlebois <charlebm@gmail.com> Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Cc: tglx@linutronix.de
2014-09-18ima: detect violations for mmaped filesRoberto Sassu
This patch fixes the detection of the 'open_writers' violation for mmaped files. before) an 'open_writers' violation is detected if the policy contains a rule with the criteria: func=FILE_CHECK mask=MAY_READ after) an 'open_writers' violation is detected if the current event matches one of the policy rules. With the old behaviour, the 'open_writers' violation is not detected in the following case: policy: measure func=FILE_MMAP mask=MAY_EXEC steps: 1) open a shared library for writing 2) execute a binary that links that shared library 3) during the binary execution, modify the shared library and save the change result: the 'open_writers' violation measurement is not present in the IMA list. Only binaries executed are protected from writes. For libraries mapped in memory there is the flag MAP_DENYWRITE for this purpose, but according to the output of 'man mmap', the mmap flag is ignored. Since ima_rdwr_violation_check() is now called by process_measurement() the information about if the inode must be measured is already provided by ima_get_action(). Thus the unnecessary function ima_must_measure() has been removed. Changes in v3 (Dmitry Kasatkin): - Violation for MMAP_CHECK function are verified since this patch - Changed patch description a bit Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-18ima: fix race condition on ima_rdwr_violation_check and process_measurementRoberto Sassu
This patch fixes a race condition between two functions that try to access the same inode. Since the i_mutex lock is held and released separately in the two functions, there may be the possibility that a violation is not correctly detected. Suppose there are two processes, A (reader) and B (writer), if the following sequence happens: A: ima_rdwr_violation_check() B: ima_rdwr_violation_check() B: process_measurement() B: starts writing the inode A: process_measurement() the ToMToU violation (a reader may be accessing a content different from that measured, due to a concurrent modification by a writer) will not be detected. To avoid this issue, the violation check and the measurement must be done atomically. This patch fixes the problem by moving the violation check inside process_measurement() when the i_mutex lock is held. Differently from the old code, the violation check is executed also for the MMAP_CHECK hook (other than for FILE_CHECK). This allows to detect ToMToU violations that are possible because shared libraries can be opened for writing while they are in use (according to the output of 'man mmap', the mmap() flag MAP_DENYWRITE is ignored). Changes in v5 (Roberto Sassu): * get iint if action is not zero * exit process_measurement() after the violation check if action is zero * reverse order process_measurement() exit cleanup (Mimi) Changes in v4 (Dmitry Kasatkin): * iint allocation is done before calling ima_rdrw_violation_check() (Suggested-by Mimi) * do not check for violations if the policy does not contain 'measure' rules (done by Roberto Sassu) Changes in v3 (Dmitry Kasatkin): * no violation checking for MMAP_CHECK function in this patch * remove use of filename from violation * removes checking if ima is enabled from ima_rdrw_violation_check * slight style change Suggested-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17ima: added ima_policy_flag variableRoberto Sassu
This patch introduces the new variable 'ima_policy_flag', whose bits are set depending on the action of the current policy rules. Only the flags IMA_MEASURE, IMA_APPRAISE and IMA_AUDIT are set. The new variable will be used to improve performance by skipping the unnecessary execution of IMA code if the policy does not contain rules with the above actions. Changes in v6 (Roberto Sassu) * do not check 'ima_initialized' before calling ima_update_policy_flag() in ima_update_policy() (suggested by Dmitry) * calling ima_update_policy_flag() moved to init_ima to co-locate with ima_initialized (Dmitry) * add/revise comments (Mimi) Changes in v5 (Roberto Sassu) * reset IMA_APPRAISE flag in 'ima_policy_flag' if 'ima_appraise' is set to zero (reported by Dmitry) * update 'ima_policy_flag' only if IMA initialization is successful (suggested by Mimi and Dmitry) * check 'ima_policy_flag' instead of 'ima_initialized' (suggested by Mimi and Dmitry) Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17ima: return an error code from ima_add_boot_aggregate()Roberto Sassu
This patch modifies ima_add_boot_aggregate() to return an error code. This way we can determine if all the initialization procedures have been executed successfully. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17ima: provide 'ima_appraise=log' kernel optionDmitry Kasatkin
The kernel boot parameter "ima_appraise" currently defines 'off', 'enforce' and 'fix' modes. When designing a policy and labeling the system, access to files are either blocked in the default 'enforce' mode or automatically fixed in the 'fix' mode. It is beneficial to be able to run the system in a logging only mode, without fixing it, in order to properly analyze the system. This patch adds a 'log' mode to run the system in a permissive mode and log the appraisal results. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-17ima: move keyring initialization to ima_init()Dmitry Kasatkin
ima_init() is used as a single place for all initializations. Experimental keyring patches used the 'late_initcall' which was co-located with the late_initcall(init_ima). When the late_initcall for the keyring initialization was abandoned, initialization moved to init_ima, though it would be more logical to move it to ima_init, where the rest of the initialization is done. This patch moves the keyring initialization to ima_init() as a preparatory step for loading the keys which will be added to ima_init() in following patches. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09integrity: base integrity subsystem kconfig options on integrityDmitry Kasatkin
The integrity subsystem has lots of options and takes more than half of the security menu. This patch consolidates the options under "integrity", which are hidden if not enabled. This change does not affect existing configurations. Re-configuration is not needed. Changes v4: - no need to change "integrity subsystem" to menuconfig as options are hidden, when not enabled. (Mimi) - add INTEGRITY Kconfig help description Changes v3: - dependency to INTEGRITY removed when behind 'if INTEGRITY' Changes v2: - previous patch moved integrity out of the 'security' menu. This version keeps integrity as a security option (Mimi). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: initialize only required templateDmitry Kasatkin
IMA uses only one template. This patch initializes only required template to avoid unnecessary memory allocations. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Reviewed-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: remove usage of filename parameterDmitry Kasatkin
In all cases except ima_bprm_check() the filename was not defined and ima_d_path() was used to find the full path. Unfortunately, the bprm filename is a relative pathname (eg. ./<dir>/filename). ima_bprm_check() selects between bprm->interp and bprm->filename. The following dump demonstrates the differences between using filename and interp. bprm->filename filename: ./foo.sh, pathname: /root/bin/foo.sh filename: ./foo.sh, pathname: /bin/dash bprm->interp filename: ./foo.sh, pathname: /root/bin/foo.sh filename: /bin/sh, pathname: /bin/dash In both cases the pathnames are currently the same. This patch removes usage of filename and interp in favor of d_absolute_path. Changes v3: - 11 extra bytes for "deleted" not needed (Mimi) - purpose "replace relative bprm filename with full pathname" (Mimi) Changes v2: - use d_absolute_path() instead of d_path to work in chroot environments. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: remove unnecessary appraisal testDmitry Kasatkin
ima_get_action() sets the "action" flags based on policy. Before collecting, measuring, appraising, or auditing the file, the "action" flag is updated based on the cached iint->flags. This patch removes the subsequent unnecessary appraisal test in ima_appraise_measurement(). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: add missing '__init' keywordsDmitry Kasatkin
Add missing keywords to the function definition to cleanup to discard initialization code. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Reviewed-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: remove unnecessary extra variableDmitry Kasatkin
'function' variable value can be changed instead of allocating extra '_func' variable. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: simplify conditional statement to improve performanceDmitry Kasatkin
Precede bit testing before string comparison makes code faster. Also refactor statement as a single line pointer assignment. Logic is following: we set 'xattr_ptr' to read xattr value when we will do appraisal or in any case when measurement template is other than 'ima'. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09integrity: remove declaration of non-existing functionsDmitry Kasatkin
Commit f381c27 "integrity: move ima inode integrity data management" (re)moved few functions but left their declarations in header files. This patch removes them and also removes duplicated declaration of integrity_iint_find(). Commit c7de7ad "ima: remove unused cleanup functions". This patch removes these definitions as well. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-09ima: pass 'opened' flag to identify newly created filesDmitry Kasatkin
Empty files and missing xattrs do not guarantee that a file was just created. This patch passes FILE_CREATED flag to IMA to reliably identify new files. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.14+
2014-09-08ima: provide flag to identify new empty filesDmitry Kasatkin
On ima_file_free(), newly created empty files are not labeled with an initial security.ima value, because the iversion did not change. Commit dff6efc "fs: fix iversion handling" introduced a change in iversion behavior. To verify this change use the shell command: $ (exec >foo) $ getfattr -h -e hex -d -m security foo This patch defines the IMA_NEW_FILE flag. The flag is initially set, when IMA detects that a new file is created, and subsequently checked on the ima_file_free() hook to set the initial security.ima value. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.14+
2014-09-02ima: fix fallback to use new_sync_read()Dmitry Kasatkin
3.16 commit aad4f8bb42af06371aa0e85bf0cd9d52c0494985 'switch simple generic_file_aio_read() users to ->read_iter()' replaced ->aio_read with ->read_iter in most of the file systems and introduced new_sync_read() as a replacement for do_sync_read(). Most of file systems set '->read' and ima_kernel_read is not affected. When ->read is not set, this patch adopts fallback call changes from the vfs_read. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.16+
2014-09-02ima: prevent buffer overflow in ima_alloc_tfm()Dmitry Kasatkin
This patch fixes the case where the file's signature/hash xattr contains an invalid hash algorithm. Although we can not verify the xattr, we still need to measure the file. Use the default IMA hash algorithm. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-09-02ima: fix ima_alloc_atfm()Mimi Zohar
The patch 3bcced39ea7d: "ima: use ahash API for file hash calculation" from Feb 26, 2014, leads to the following static checker warning: security/integrity/ima/ima_crypto.c:204 ima_alloc_atfm()          error: buffer overflow 'hash_algo_name' 17 <= 17 Unlike shash tfm memory, which is allocated on initialization, the ahash tfm memory allocation is deferred until needed. This patch fixes the case where ima_ahash_tfm has not yet been allocated and the file's signature/hash xattr contains an invalid hash algorithm. Although we can not verify the xattr, we still need to measure the file. Use the default IMA hash algorithm. Changelog: - set valid algo before testing tfm - based on Dmitry's comment Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-07-25ima: add support for measuring and appraising firmwareMimi Zohar
The "security: introduce kernel_fw_from_file hook" patch defined a new security hook to evaluate any loaded firmware that wasn't built into the kernel. This patch defines ima_fw_from_file(), which is called from the new security hook, to measure and/or appraise the loaded firmware's integrity. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2014-07-17ima: define '.ima' as a builtin 'trusted' keyringMimi Zohar
Require all keys added to the IMA keyring be signed by an existing trusted key on the system trusted keyring. Changelog v6: - remove ifdef CONFIG_IMA_TRUSTED_KEYRING in C code - Dmitry - update Kconfig dependency and help - select KEYS_DEBUG_PROC_KEYS - Dmitry Changelog v5: - Move integrity_init_keyring() to init_ima() - Dmitry - reset keyring[id] on failure - Dmitry Changelog v1: - don't link IMA trusted keyring to user keyring Changelog: - define stub integrity_init_keyring() function (reported-by Fengguang Wu) - differentiate between regular and trusted keyring names. - replace printk with pr_info (D. Kasatkin) - only make the IMA keyring a trusted keyring (reported-by D. Kastatkin) - define stub integrity_init_keyring() definition based on CONFIG_INTEGRITY_SIGNATURE, not CONFIG_INTEGRITY_ASYMMETRIC_KEYS. (reported-by Jim Davis) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Acked-by: David Howells <dhowells@redhat.com>
2014-07-17ima: provide double buffering for hash calculationDmitry Kasatkin
The asynchronous hash API allows initiating a hash calculation and then performing other tasks, while waiting for the hash calculation to complete. This patch introduces usage of double buffering for simultaneous hashing and reading of the next chunk of data from storage. Changes in v3: - better comments Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17ima: introduce multi-page collect buffersDmitry Kasatkin
Use of multiple-page collect buffers reduces: 1) the number of block IO requests 2) the number of asynchronous hash update requests Second is important for HW accelerated hashing, because significant amount of time is spent for preparation of hash update operation, which includes configuring acceleration HW, DMA engine, etc... Thus, HW accelerators are more efficient when working on large chunks of data. This patch introduces usage of multi-page collect buffers. Buffer size can be specified using 'ahash_bufsize' module parameter. Default buffer size is 4096 bytes. Changes in v3: - kernel parameter replaced with module parameter Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17ima: use ahash API for file hash calculationDmitry Kasatkin
Async hash API allows the use of HW acceleration for hash calculation. It may give significant performance gain and/or reduce power consumption, which might be very beneficial for battery powered devices. This patch introduces hash calculation using ahash API. ahash performance depends on the data size and the particular HW. Depending on the specific system, shash performance may be better. This patch defines 'ahash_minsize' module parameter, which is used to define the minimal file size to use with ahash. If this minimum file size is not set or the file is smaller than defined by the parameter, shash will be used. Changes in v3: - kernel parameter replaced with module parameter - pr_crit replaced with pr_crit_ratelimited - more comment changes - Mimi Changes in v2: - ima_ahash_size became as ima_ahash - ahash pre-allocation moved out from __init code to be able to use ahash crypto modules. Ahash allocated once on the first use. - hash calculation falls back to shash if ahash allocation/calculation fails - complex initialization separated from variable declaration - improved comments Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17audit: fix dangling keywords in integrity ima message outputRichard Guy Briggs
Replace spaces in op keyword labels in log output since userspace audit tools can't parse orphaned keywords. Reported-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17ima: delay template descriptor lookup until useDmitry Kasatkin
process_measurement() always calls ima_template_desc_current(), including when an IMA policy has not been defined. This patch delays template descriptor lookup until action is determined. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17ima: remove unnecessary i_mutex locking from ima_rdwr_violation_check()Dmitry Kasatkin
Before 2.6.39 inode->i_readcount was maintained by IMA. It was not atomic and protected using spinlock. For 2.6.39, i_readcount was converted to atomic and maintaining was moved VFS layer. Spinlock for some unclear reason was replaced by i_mutex. After analyzing the code, we came to conclusion that i_mutex locking is unnecessary, especially when an IMA policy has not been defined. This patch removes i_mutex locking from ima_rdwr_violation_check(). Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12ima: introduce ima_kernel_read()Dmitry Kasatkin
Commit 8aac62706 "move exit_task_namespaces() outside of exit_notify" introduced the kernel opps since the kernel v3.10, which happens when Apparmor and IMA-appraisal are enabled at the same time. ---------------------------------------------------------------------- [ 106.750167] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 106.750221] IP: [<ffffffff811ec7da>] our_mnt+0x1a/0x30 [ 106.750241] PGD 0 [ 106.750254] Oops: 0000 [#1] SMP [ 106.750272] Modules linked in: cuse parport_pc ppdev bnep rfcomm bluetooth rpcsec_gss_krb5 nfsd auth_rpcgss nfs_acl nfs lockd sunrpc fscache dm_crypt intel_rapl x86_pkg_temp_thermal intel_powerclamp kvm_intel snd_hda_codec_hdmi kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd snd_hda_codec_realtek dcdbas snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_seq_midi snd_seq_midi_event snd_rawmidi psmouse snd_seq microcode serio_raw snd_timer snd_seq_device snd soundcore video lpc_ich coretemp mac_hid lp parport mei_me mei nbd hid_generic e1000e usbhid ahci ptp hid libahci pps_core [ 106.750658] CPU: 6 PID: 1394 Comm: mysqld Not tainted 3.13.0-rc7-kds+ #15 [ 106.750673] Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A08 09/19/2012 [ 106.750689] task: ffff8800de804920 ti: ffff880400fca000 task.ti: ffff880400fca000 [ 106.750704] RIP: 0010:[<ffffffff811ec7da>] [<ffffffff811ec7da>] our_mnt+0x1a/0x30 [ 106.750725] RSP: 0018:ffff880400fcba60 EFLAGS: 00010286 [ 106.750738] RAX: 0000000000000000 RBX: 0000000000000100 RCX: ffff8800d51523e7 [ 106.750764] RDX: ffffffffffffffea RSI: ffff880400fcba34 RDI: ffff880402d20020 [ 106.750791] RBP: ffff880400fcbae0 R08: 0000000000000000 R09: 0000000000000001 [ 106.750817] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8800d5152300 [ 106.750844] R13: ffff8803eb8df510 R14: ffff880400fcbb28 R15: ffff8800d51523e7 [ 106.750871] FS: 0000000000000000(0000) GS:ffff88040d200000(0000) knlGS:0000000000000000 [ 106.750910] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 106.750935] CR2: 0000000000000018 CR3: 0000000001c0e000 CR4: 00000000001407e0 [ 106.750962] Stack: [ 106.750981] ffffffff813434eb ffff880400fcbb20 ffff880400fcbb18 0000000000000000 [ 106.751037] ffff8800de804920 ffffffff8101b9b9 0001800000000000 0000000000000100 [ 106.751093] 0000010000000000 0000000000000002 000000000000000e ffff8803eb8df500 [ 106.751149] Call Trace: [ 106.751172] [<ffffffff813434eb>] ? aa_path_name+0x2ab/0x430 [ 106.751199] [<ffffffff8101b9b9>] ? sched_clock+0x9/0x10 [ 106.751225] [<ffffffff8134a68d>] aa_path_perm+0x7d/0x170 [ 106.751250] [<ffffffff8101b945>] ? native_sched_clock+0x15/0x80 [ 106.751276] [<ffffffff8134aa73>] aa_file_perm+0x33/0x40 [ 106.751301] [<ffffffff81348c5e>] common_file_perm+0x8e/0xb0 [ 106.751327] [<ffffffff81348d78>] apparmor_file_permission+0x18/0x20 [ 106.751355] [<ffffffff8130c853>] security_file_permission+0x23/0xa0 [ 106.751382] [<ffffffff811c77a2>] rw_verify_area+0x52/0xe0 [ 106.751407] [<ffffffff811c789d>] vfs_read+0x6d/0x170 [ 106.751432] [<ffffffff811cda31>] kernel_read+0x41/0x60 [ 106.751457] [<ffffffff8134fd45>] ima_calc_file_hash+0x225/0x280 [ 106.751483] [<ffffffff8134fb52>] ? ima_calc_file_hash+0x32/0x280 [ 106.751509] [<ffffffff8135022d>] ima_collect_measurement+0x9d/0x160 [ 106.751536] [<ffffffff810b552d>] ? trace_hardirqs_on+0xd/0x10 [ 106.751562] [<ffffffff8134f07c>] ? ima_file_free+0x6c/0xd0 [ 106.751587] [<ffffffff81352824>] ima_update_xattr+0x34/0x60 [ 106.751612] [<ffffffff8134f0d0>] ima_file_free+0xc0/0xd0 [ 106.751637] [<ffffffff811c9635>] __fput+0xd5/0x300 [ 106.751662] [<ffffffff811c98ae>] ____fput+0xe/0x10 [ 106.751687] [<ffffffff81086774>] task_work_run+0xc4/0xe0 [ 106.751712] [<ffffffff81066fad>] do_exit+0x2bd/0xa90 [ 106.751738] [<ffffffff8173c958>] ? retint_swapgs+0x13/0x1b [ 106.751763] [<ffffffff8106780c>] do_group_exit+0x4c/0xc0 [ 106.751788] [<ffffffff81067894>] SyS_exit_group+0x14/0x20 [ 106.751814] [<ffffffff8174522d>] system_call_fastpath+0x1a/0x1f [ 106.751839] Code: c3 0f 1f 44 00 00 55 48 89 e5 e8 22 fe ff ff 5d c3 0f 1f 44 00 00 55 65 48 8b 04 25 c0 c9 00 00 48 8b 80 28 06 00 00 48 89 e5 5d <48> 8b 40 18 48 39 87 c0 00 00 00 0f 94 c0 c3 0f 1f 80 00 00 00 [ 106.752185] RIP [<ffffffff811ec7da>] our_mnt+0x1a/0x30 [ 106.752214] RSP <ffff880400fcba60> [ 106.752236] CR2: 0000000000000018 [ 106.752258] ---[ end trace 3c520748b4732721 ]--- ---------------------------------------------------------------------- The reason for the oops is that IMA-appraisal uses "kernel_read()" when file is closed. kernel_read() honors LSM security hook which calls Apparmor handler, which uses current->nsproxy->mnt_ns. The 'guilty' commit changed the order of cleanup code so that nsproxy->mnt_ns was not already available for Apparmor. Discussion about the issue with Al Viro and Eric W. Biederman suggested that kernel_read() is too high-level for IMA. Another issue, except security checking, that was identified is mandatory locking. kernel_read honors it as well and it might prevent IMA from calculating necessary hash. It was suggested to use simplified version of the function without security and locking checks. This patch introduces special version ima_kernel_read(), which skips security and mandatory locking checking. It prevents the kernel oops to happen. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org>
2014-06-12ima: check inode integrity cache in violation checkDmitry Kasatkin
When IMA did not support ima-appraisal, existance of the S_IMA flag clearly indicated that the file was measured. With IMA appraisal S_IMA flag indicates that file was measured and/or appraised. Because of this, when measurement is not enabled by the policy, violations are still reported. To differentiate between measurement and appraisal policies this patch checks the inode integrity cache flags. The IMA_MEASURED flag indicates whether the file was actually measured, while the IMA_MEASURE flag indicates whether the file should be measured. Unfortunately, the IMA_MEASURED flag is reset to indicate the file needs to be re-measured. Thus, this patch checks the IMA_MEASURE flag. This patch limits the false positive violation reports, but does not fix it entirely. The IMA_MEASURE/IMA_MEASURED flags are indications that, at some point in time, the file opened for read was in policy, but might not be in policy now (eg. different uid). Other changes would be needed to further limit false positive violation reports. Changelog: - expanded patch description based on conversation with Roberto (Mimi) Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12ima: prevent unnecessary policy checkingDmitry Kasatkin
ima_rdwr_violation_check is called for every file openning. The function checks the policy even when violation condition is not met. It causes unnecessary policy checking. This patch does policy checking only if violation condition is met. Changelog: - check writecount is greater than zero (Mimi) Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-12ima: prevent new digsig xattr from being replacedMimi Zohar
Even though a new xattr will only be appraised on the next access, set the DIGSIG flag to prevent a signature from being replaced with a hash on file close. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-06-03ima: audit log files opened with O_DIRECT flagMimi Zohar
Files are measured or appraised based on the IMA policy. When a file, in policy, is opened with the O_DIRECT flag, a deadlock occurs. The first attempt at resolving this lockdep temporarily removed the O_DIRECT flag and restored it, after calculating the hash. The second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this flag, do_blockdev_direct_IO() would skip taking the i_mutex a second time. The third attempt, by Dmitry Kasatkin, resolves the i_mutex locking issue, by re-introducing the IMA mutex, but uncovered another problem. Reading a file with O_DIRECT flag set, writes directly to userspace pages. A second patch allocates a user-space like memory. This works for all IMA hooks, except ima_file_free(), which is called on __fput() to recalculate the file hash. Until this last issue is addressed, do not 'collect' the measurement for measuring, appraising, or auditing files opened with the O_DIRECT flag set. Based on policy, permit or deny file access. This patch defines a new IMA policy rule option named 'permit_directio'. Policy rules could be defined, based on LSM or other criteria, to permit specific applications to open files with the O_DIRECT flag set. Changelog v1: - permit or deny file access based IMA policy rules Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Cc: <stable@vger.kernel.org>
2014-03-07ima: skip memory allocation for empty filesDmitry Kasatkin
Memory allocation is unnecessary for empty files. This patch calculates the hash without memory allocation. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07ima: return d_name.name if d_path failsDmitry Kasatkin
This is a small refactoring so ima_d_path() returns dentry name if path reconstruction fails. It simplifies callers actions and removes code duplication. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07integrity: fix checkpatch errorsDmitry Kasatkin
Between checkpatch changes (eg. sizeof) and inconsistencies between Lindent and checkpatch, unfixed checkpatch errors make it difficult to see new errors. This patch fixes them. Some lines with over 80 chars remained unchanged to improve code readability. The "extern" keyword is removed from internal evm.h to make it consistent with internal ima.h. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07ima: fix erroneous removal of security.ima xattrDmitry Kasatkin
ima_inode_post_setattr() calls ima_must_appraise() to check if the file needs to be appraised. If it does not then it removes security.ima xattr. With original policy matching code it might happen that even file needs to be appraised with FILE_CHECK hook, it might not be for POST_SETATTR hook. 'security.ima' might be erronously removed. This patch treats POST_SETATTR as special wildcard function and will cause ima_must_appraise() to be true if any of the hooks rules matches. security.ima will not be removed if any of the hooks would require appraisal. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07security: integrity: Use a more current logging styleJoe Perches
Convert printks to pr_<level>. Add pr_fmt. Remove embedded prefixes. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07ima: reduce memory usage when a template containing the n field is usedRoberto Sassu
Before this change, to correctly calculate the template digest for the 'ima' template, the event name field (id: 'n') length was set to the fixed size of 256 bytes. This patch reduces the length of the event name field to the string length incremented of one (to make room for the termination character '\0') and handles the specific case of the digest calculation for the 'ima' template directly in ima_calc_field_array_hash_tfm(). Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07ima: restore the original behavior for sending data with ima templateRoberto Sassu
With the new template mechanism introduced in IMA since kernel 3.13, the format of data sent through the binary_runtime_measurements interface is slightly changed. Now, for a generic measurement, the format of template data (after the template name) is: template_len | field1_len | field1 | ... | fieldN_len | fieldN In addition, fields containing a string now include the '\0' termination character. Instead, the format for the 'ima' template should be: SHA1 digest | event name length | event name It must be noted that while in the IMA 3.13 code 'event name length' is 'IMA_EVENT_NAME_LEN_MAX + 1' (256 bytes), so that the template digest is calculated correctly, and 'event name' contains '\0', in the pre 3.13 code 'event name length' is exactly the string length and 'event name' does not contain the termination character. The patch restores the behavior of the IMA code pre 3.13 for the 'ima' template so that legacy userspace tools obtain a consistent behavior when receiving data from the binary_runtime_measurements interface regardless of which kernel version is used. Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Cc: <stable@vger.kernel.org> # 3.3.13: 3ce1217 ima: define template fields library Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-03-07ima: use static const char array definitionsMimi Zohar
A const char pointer allocates memory for a pointer as well as for a string, This patch replaces a number of the const char pointers throughout IMA, with a static const char array. Suggested-by: David Howells <dhowells@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com>
2014-03-04ima: new helper: file_inode(file)Libo Chen
Replace "file->f_dentry->d_inode" with the new file_inode() helper function. Signed-off-by: Libo Chen <clbchenlibo.chen@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-02-06security: replace strict_strto*() with kstrto*()Jingoo Han
The usage of strict_strto*() is not preferred, because strict_strto*() is obsolete. Thus, kstrto*() should be used. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2014-01-06Merge to v3.13-rc7 for prerequisite changes in the Xen code for TPMJames Morris
2014-01-03ima: remove unneeded size_limit argument from ima_eventdigest_init_common()Roberto Sassu
This patch removes the 'size_limit' argument from ima_eventdigest_init_common(). Since the 'd' field will never include the hash algorithm as prefix and the 'd-ng' will always have it, we can use the hash algorithm to differentiate the two cases in the modified function (it is equal to HASH_ALGO__LAST in the first case, the opposite in the second). Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-01-03ima: pass HASH_ALGO__LAST as hash algo in ima_eventdigest_init()Roberto Sassu
Replace the '-1' value with HASH_ALGO__LAST in ima_eventdigest_init() as the called function ima_eventdigest_init_common() expects an unsigned char. Fix commit: 4d7aeee ima: define new template ima-ng and template fields d-ng and n-ng Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-01-03ima: change the default hash algorithm to SHA1 in ima_eventdigest_ng_init()Roberto Sassu
Replace HASH_ALGO__LAST with HASH_ALGO_SHA1 as the initial value of the hash algorithm so that the prefix 'sha1:' is added to violation digests. Fix commit: 4d7aeee ima: define new template ima-ng and template fields d-ng and n-ng Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Cc: <stable@vger.kernel.org> # 3.13.x Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-12-02ima: properly free ima_template_entry structuresRoberto Sassu
The new templates management mechanism records information associated to an event into an array of 'ima_field_data' structures and makes it available through the 'template_data' field of the 'ima_template_entry' structure (the element of the measurements list created by IMA). Since 'ima_field_data' contains dynamically allocated data (which length varies depending on the data associated to a selected template field), it is not enough to just free the memory reserved for a 'ima_template_entry' structure if something goes wrong. This patch creates the new function ima_free_template_entry() which walks the array of 'ima_field_data' structures, frees the memory referenced by the 'data' pointer and finally the space reserved for the 'ima_template_entry' structure. Further, it replaces existing kfree() that have a pointer to an 'ima_template_entry' structure as argument with calls to the new function. Fixes: a71dc65: ima: switch to new template management mechanism Signed-off-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>