kernel/linux.git/security, branch v5.8.17

ima: Fix NULL pointer dereference in ima_file_hash

2020-10-29T09:07:38+00:00

[ Upstream commit aa662fc04f5b290b3979332588bf8d812b189962 ] ima_file_hash can be called when there is no iint->ima_hash available even though the inode exists in the integrity cache. It is fairly common for a file to not have a hash. (e.g. an mknodat, prior to the file being closed). Another example where this can happen (suggested by Jann Horn): Process A does: while(1) { unlink("/tmp/imafoo"); fd = open("/tmp/imafoo", O_RDWR|O_CREAT|O_TRUNC, 0700); if (fd == -1) { perror("open"); continue; } write(fd, "A", 1); close(fd); } and Process B does: while (1) { int fd = open("/tmp/imafoo", O_RDONLY); if (fd == -1) continue; char *mapping = mmap(NULL, 0x1000, PROT_READ|PROT_EXEC, MAP_PRIVATE, fd, 0); if (mapping != MAP_FAILED) munmap(mapping, 0x1000); close(fd); } Due to the race to get the iint->mutex between ima_file_hash and process_measurement iint->ima_hash could still be NULL. Fixes: 6beea7afcc72 ("ima: add the ability to query the cached hash of a given file") Signed-off-by: KP Singh Reviewed-by: Florent Revest Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Don't ignore errors from crypto_shash_update()

2020-10-29T09:07:12+00:00

commit 60386b854008adc951c470067f90a2d85b5d520f upstream. Errors returned by crypto_shash_update() are not checked in ima_calc_boot_aggregate_tfm() and thus can be overwritten at the next iteration of the loop. This patch adds a check after calling crypto_shash_update() and returns immediately if the result is not zero. Cc: stable@vger.kernel.org Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider") Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

device_cgroup: Fix RCU list debugging warning

2020-10-01T15:36:23+00:00

[ Upstream commit bc62d68e2a0a69fcdcf28aca8edb01abf306b698 ] exceptions may be traversed using list_for_each_entry_rcu() outside of an RCU read side critical section BUT under the protection of decgroup_mutex. Hence add the corresponding lockdep expression to fix the following false-positive warning: [ 2.304417] ============================= [ 2.304418] WARNING: suspicious RCU usage [ 2.304420] 5.5.4-stable #17 Tainted: G E [ 2.304422] ----------------------------- [ 2.304424] security/device_cgroup.c:355 RCU-list traversed in non-reader section!! Signed-off-by: Amol Grover Signed-off-by: James Morris Signed-off-by: Sasha Levin

ima: Fail rule parsing when appraise_flag=blacklist is unsupportable

2020-08-21T11:15:09+00:00

[ Upstream commit 5f3e92657bbfb63ad3109433d843c89996114b03 ] Verifying that a file hash is not blacklisted is currently only supported for files with appended signatures (modsig). In the future, this might change. For now, the "appraise_flag" option is only appropriate for appraise actions and its "blacklist" value is only appropriate when CONFIG_IMA_APPRAISE_MODSIG is enabled and "appraise_flag=blacklist" is only appropriate when "appraise_type=imasig|modsig" is also present. Make this clear at policy load so that IMA policy authors don't assume that other uses of "appraise_flag=blacklist" are supported. Fixes: 273df864cf74 ("ima: Check against blacklisted hashes for files with modsig") Signed-off-by: Tyler Hicks Reivewed-by: Nayna Jain Tested-by: Nayna Jain Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

Smack: prevent underflow in smk_set_cipso()

2020-08-19T06:26:46+00:00

[ Upstream commit 42a2df3e829f3c5562090391b33714b2e2e5ad4a ] We have an upper bound on "maplevel" but forgot to check for negative values. Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel") Signed-off-by: Dan Carpenter Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

Smack: fix another vsscanf out of bounds

2020-08-19T06:26:45+00:00

[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ] This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in vsscanf") where we added a bounds check on "rule". Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4") Signed-off-by: Dan Carpenter Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

ima: Fail rule parsing when the KEY_CHECK hook is combined with an invalid cond

2020-08-19T06:26:37+00:00

[ Upstream commit eb624fe214a2e156ddafd9868377cf91499f789d ] The KEY_CHECK function only supports the uid, pcr, and keyrings conditionals. Make this clear at policy load so that IMA policy authors don't assume that other conditionals are supported. Fixes: 5808611cccb2 ("IMA: Add KEY_CHECK func to measure keys") Signed-off-by: Tyler Hicks Reviewed-by: Lakshmi Ramasubramanian Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Fail rule parsing when the KEXEC_CMDLINE hook is combined with an invalid cond

2020-08-19T06:26:37+00:00

[ Upstream commit db2045f5892a9db7354442bf77f9b03b50ff9ee1 ] The KEXEC_CMDLINE hook function only supports the pcr conditional. Make this clear at policy load so that IMA policy authors don't assume that other conditionals are supported. Since KEXEC_CMDLINE's inception, ima_match_rules() has always returned true on any loaded KEXEC_CMDLINE rule without any consideration for other conditionals present in the rule. Make it clear that pcr is the only supported KEXEC_CMDLINE conditional by returning an error during policy load. An example of why this is a problem can be explained with the following rule: dont_measure func=KEXEC_CMDLINE obj_type=foo_t An IMA policy author would have assumed that rule is valid because the parser accepted it but the result was that measurements for all KEXEC_CMDLINE operations would be disabled. Fixes: b0935123a183 ("IMA: Define a new hook to measure the kexec boot command line arguments") Signed-off-by: Tyler Hicks Reviewed-by: Mimi Zohar Reviewed-by: Lakshmi Ramasubramanian Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Fail rule parsing when buffer hook functions have an invalid action

2020-08-19T06:26:37+00:00

[ Upstream commit 712183437ebebc89cd086ef96cf9a521fd97fd09 ] Buffer based hook functions, such as KEXEC_CMDLINE and KEY_CHECK, can only measure. The process_buffer_measurement() function quietly ignores all actions except measure so make this behavior clear at the time of policy load. The parsing of the keyrings conditional had a check to ensure that it was only specified with measure actions but the check should be on the hook function and not the keyrings conditional since "appraise func=KEY_CHECK" is not a valid rule. Fixes: b0935123a183 ("IMA: Define a new hook to measure the kexec boot command line arguments") Fixes: 5808611cccb2 ("IMA: Add KEY_CHECK func to measure keys") Signed-off-by: Tyler Hicks Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

ima: Free the entire rule if it fails to parse

2020-08-19T06:26:36+00:00

[ Upstream commit 2bdd737c5687d6dec30e205953146ede8a87dbdd ] Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry members, such as .fsname and .keyrings, when an error is encountered during rule parsing. Set the args_p pointer to NULL after freeing it in the error path of ima_lsm_rule_init() so that it isn't freed twice. This fixes a memory leak seen when loading an rule that contains an additional piece of allocated memory, such as an fsname, followed by an invalid conditional: # echo "measure fsname=tmpfs bad=cond" > /sys/kernel/security/ima/policy -bash: echo: write error: Invalid argument # echo scan > /sys/kernel/debug/kmemleak # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff98e7e4ece6c0 (size 8): comm "bash", pid 672, jiffies 4294791843 (age 21.855s) hex dump (first 8 bytes): 74 6d 70 66 73 00 6b a5 tmpfs.k. backtrace: [<00000000abab7413>] kstrdup+0x2e/0x60 [<00000000f11ede32>] ima_parse_add_rule+0x7d4/0x1020 [<00000000f883dd7a>] ima_write_policy+0xab/0x1d0 [<00000000b17cf753>] vfs_write+0xde/0x1d0 [<00000000b8ddfdea>] ksys_write+0x68/0xe0 [<00000000b8e21e87>] do_syscall_64+0x56/0xa0 [<0000000089ea7b98>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name") Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") Signed-off-by: Tyler Hicks Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin