kernel/linux.git/security/smack/smackfs.c, branch linux-4.4.y

smackfs: use netlbl_cfg_cipsov4_del() for deleting cipso_v4_doi

2021-11-26T10:58:40+00:00

[ Upstream commit 0934ad42bb2c5df90a1b9de690f93de735b622fe ] syzbot is reporting UAF at cipso_v4_doi_search() [1], for smk_cipso_doi() is calling kfree() without removing from the cipso_v4_doi_list list after netlbl_cfg_cipsov4_map_add() returned an error. We need to use netlbl_cfg_cipsov4_del() in order to remove from the list and wait for RCU grace period before kfree(). Link: https://syzkaller.appspot.com/bug?extid=93dba5b91f0fed312cbd [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Fixes: 6c2e8ac0953fccdd ("netlabel: Update kernel configuration API") Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

smackfs: use __GFP_NOFAIL for smk_cipso_doi()

2021-11-26T10:58:38+00:00

[ Upstream commit f91488ee15bd3cac467e2d6a361fc2d34d1052ae ] syzbot is reporting kernel panic at smk_cipso_doi() due to memory allocation fault injection [1]. The reason for need to use panic() was not explained. But since no fix was proposed for 18 months, for now let's use __GFP_NOFAIL for utilizing syzbot resource on other bugs. Link: https://syzkaller.appspot.com/bug?extid=89731ccb6fec15ce1c22 [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

smackfs: Fix use-after-free in netlbl_catmap_walk()

2021-11-26T10:58:37+00:00

[ Upstream commit 0817534ff9ea809fac1322c5c8c574be8483ea57 ] Syzkaller reported use-after-free bug as described in [1]. The bug is triggered when smk_set_cipso() tries to free stale category bitmaps while there are concurrent reader(s) using the same bitmaps. Wait for RCU grace period to finish before freeing the category bitmaps in smk_set_cipso(). This makes sure that there are no more readers using the stale bitmaps and freeing them should be safe. [1] https://lore.kernel.org/netdev/000000000000a814c505ca657a4e@google.com/ Reported-by: syzbot+3f91de0b813cc3d19a80@syzkaller.appspotmail.com Signed-off-by: Pawan Gupta Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

Smack: prevent underflow in smk_set_cipso()

2020-08-21T08:53:02+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

2020-08-21T08:53:02+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

Smack: fix use-after-free in smk_write_relabel_self()

2020-08-21T08:52:57+00:00

commit beb4ee6770a89646659e6a2178538d2b13e2654e upstream. smk_write_relabel_self() frees memory from the task's credentials with no locking, which can easily cause a use-after-free because multiple tasks can share the same credentials structure. Fix this by using prepare_creds() and commit_creds() to correctly modify the task's credentials. Reproducer for "BUG: KASAN: use-after-free in smk_write_relabel_self": #include #include #include static void *thrproc(void *arg) { int fd = open("/sys/fs/smackfs/relabel-self", O_WRONLY); for (;;) write(fd, "foo", 3); } int main() { pthread_t t; pthread_create(&t, NULL, thrproc, NULL); thrproc(NULL); } Reported-by: syzbot+e6416dabb497a650da40@syzkaller.appspotmail.com Fixes: 38416e53936e ("Smack: limited capability for changing process label") Cc: # v4.4+ Signed-off-by: Eric Biggers Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

Smack: slab-out-of-bounds in vsscanf

2020-06-20T08:23:19+00:00

commit 84e99e58e8d1e26f04c097f4266e431a33987f36 upstream. Add barrier to soob. Return -EOVERFLOW if the buffer is exceeded. Suggested-by: Hillf Danton Reported-by: syzbot+bfdd4a2f07be52351350@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

Smack: limited capability for changing process label

2015-10-19T19:06:47+00:00

This feature introduces new kernel interface: - /relabel-self - for setting transition labels list This list is used to control smack label transition mechanism. List is set by, and per process. Process can transit to new label only if label is on the list. Only process with CAP_MAC_ADMIN capability can add labels to this list. With this list, process can change it's label without CAP_MAC_ADMIN but only once. After label changing, list is unset. Changes in v2: * use list_for_each_entry instead of _rcu during label write * added missing description in security/Smack.txt Changes in v3: * squashed into one commit Changes in v4: * switch from global list to per-task list * since the per-task list is accessed only by the task itself there is no need to use synchronization mechanisms on it Changes in v5: * change smackfs interface of relabel-self to the one used for onlycap multiple labels are accepted, separated by space, which replace the previous list upon write Signed-off-by: Zbigniew Jasinski Signed-off-by: Rafal Krypa Acked-by: Casey Schaufler

Smack: Minor initialisation improvement

2015-10-09T22:13:24+00:00

This change has two goals: - delay the setting of 'smack_enabled' until it will be really effective - ensure that smackfs is valid only if 'smack_enabled' is set (it is already the case in smack_netfilter.c) Signed-off-by: José Bollo Acked-by: Casey Schaufler

Smack: fix a NULL dereference in wrong smack_import_entry() usage

2015-10-09T22:12:46+00:00

'commit e774ad683f42 ("smack: pass error code through pointers")' made this function return proper error codes instead of NULL. Reflect that. This is a fix for a NULL dereference introduced in 'commit 21abb1ec414c ("Smack: IPv6 host labeling")' echo "$SOME_IPV6_ADDR \"test" > /smack/ipv6host (this should return EINVAL, it doesn't) cat /smack/ipv6host (derefences 0x000a) Signed-off-by: Lukasz Pawelczyk Acked-by: Casey Schaufler