kernel/linux.git/security/smack, branch v4.14.263

smackfs: use netlbl_cfg_cipsov4_del() for deleting cipso_v4_doi

2021-11-26T10:40:31+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()

2021-11-26T10:40:28+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()

2021-11-26T10:40:26+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: Fix wrong semantics in smk_access_entry()

2021-09-22T09:45:27+00:00

[ Upstream commit 6d14f5c7028eea70760df284057fe198ce7778dd ] In the smk_access_entry() function, if no matching rule is found in the rust_list, a negative error code will be used to perform bit operations with the MAY_ enumeration value. This is semantically wrong. This patch fixes this issue. Signed-off-by: Tianjia Zhang Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin

smackfs: restrict bytes count in smk_set_cipso()

2021-07-20T14:17:48+00:00

commit 49ec114a6e62d8d320037ce71c1aaf9650b3cafd upstream. Oops, I failed to update subject line. From 07571157c91b98ce1a4aa70967531e64b78e8346 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 12 Apr 2021 22:25:06 +0900 Subject: smackfs: restrict bytes count in smk_set_cipso() Commit 7ef4c19d245f3dc2 ("smackfs: restrict bytes count in smackfs write functions") missed that count > SMK_CIPSOMAX check applies to only format == SMK_FIXED24_FMT case. Reported-by: syzbot Signed-off-by: Tetsuo Handa Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

smackfs: restrict bytes count in smackfs write functions

2021-03-07T10:27:43+00:00

commit 7ef4c19d245f3dc233fd4be5acea436edd1d83d8 upstream. syzbot found WARNINGs in several smackfs write operations where bytes count is passed to memdup_user_nul which exceeds GFP MAX_ORDER. Check count size if bigger than PAGE_SIZE. Per smackfs doc, smk_write_net4addr accepts any label or -CIPSO, smk_write_net6addr accepts any label or -DELETE. I couldn't find any general rule for other label lengths except SMK_LABELLEN, SMK_LONGLABEL, SMK_CIPSOMAX which are documented. Let's constrain, in general, smackfs label lengths for PAGE_SIZE. Although fuzzer crashes write to smackfs/netlabel on 0x400000 length. Here is a quick way to reproduce the WARNING: python -c "print('A' * 0x400000)" > /sys/fs/smackfs/netlabel Reported-by: syzbot+a71a442385a0b2815497@syzkaller.appspotmail.com Signed-off-by: Sabyrzhan Tasbolatov Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman

Smack: prevent underflow in smk_set_cipso()

2020-08-21T07:48:11+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

2020-08-21T07:48:11+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()

2020-08-21T07:48:02+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

2020-06-20T08:25:05+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