kernel/linux.git/security/selinux, branch v4.9.104

selinux: do not check open permission on sockets

2018-04-13T17:48:04+00:00

[ Upstream commit ccb544781d34afdb73a9a73ae53035d824d193bf ] open permission is currently only defined for files in the kernel (COMMON_FILE_PERMS rather than COMMON_FILE_SOCK_PERMS). Construction of an artificial test case that tries to open a socket via /proc/pid/fd will generate a recvfrom avc denial because recvfrom and open happen to map to the same permission bit in socket vs file classes. open of a socket via /proc/pid/fd is not supported by the kernel regardless and will ultimately return ENXIO. But we hit the permission check first and can thus produce these odd/misleading denials. Omit the open check when operating on a socket. Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

selinux: Remove redundant check for unknown labeling behavior

2018-04-08T10:12:47+00:00

commit 270e8573145a26de924e2dc644596332d400445b upstream. The check is already performed in ocontext_read() when the policy is loaded. Removing the array also fixes the following warning when building with clang: security/selinux/hooks.c:338:20: error: variable 'labeling_behaviors' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] Signed-off-by: Matthias Kaehlcke Acked-by: Stephen Smalley Signed-off-by: Paul Moore Cc: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

selinux: Remove unnecessary check of array base in selinux_set_mapping()

2018-04-08T10:12:44+00:00

commit 342e91578eb6909529bc7095964cd44b9c057c4e upstream. 'perms' will never be NULL since it isn't a plain pointer but an array of u32 values. This fixes the following warning when building with clang: security/selinux/ss/services.c:158:16: error: address of array 'p_in->perms' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion] while (p_in->perms && p_in->perms[k]) { Signed-off-by: Matthias Kaehlcke Signed-off-by: Paul Moore Cc: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

selinux: check for address length in selinux_socket_bind()

2018-03-22T08:17:38+00:00

[ Upstream commit e2f586bd83177d22072b275edd4b8b872daba924 ] KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of uninitialized memory in selinux_socket_bind(): ================================================================== BUG: KMSAN: use of unitialized memory inter: 0 CPU: 3 PID: 1074 Comm: packet2 Tainted: G B 4.8.0-rc6+ #1916 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 0000000000000000 ffff8800882ffb08 ffffffff825759c8 ffff8800882ffa48 ffffffff818bf551 ffffffff85bab870 0000000000000092 ffffffff85bab550 0000000000000000 0000000000000092 00000000bb0009bb 0000000000000002 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [] dump_stack+0x238/0x290 lib/dump_stack.c:51 [] kmsan_report+0x276/0x2e0 mm/kmsan/kmsan.c:1008 [] __msan_warning+0x5b/0xb0 mm/kmsan/kmsan_instr.c:424 [] selinux_socket_bind+0xf41/0x1080 security/selinux/hooks.c:4288 [] security_socket_bind+0x1ec/0x240 security/security.c:1240 [] SYSC_bind+0x358/0x5f0 net/socket.c:1366 [] SyS_bind+0x82/0xa0 net/socket.c:1356 [] do_syscall_64+0x58/0x70 arch/x86/entry/common.c:292 [] entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.o:? chained origin: 00000000ba6009bb [] save_stack_trace+0x27/0x50 arch/x86/kernel/stacktrace.c:67 [< inline >] kmsan_save_stack_with_flags mm/kmsan/kmsan.c:322 [< inline >] kmsan_save_stack mm/kmsan/kmsan.c:337 [] kmsan_internal_chain_origin+0x118/0x1e0 mm/kmsan/kmsan.c:530 [] __msan_set_alloca_origin4+0xc3/0x130 mm/kmsan/kmsan_instr.c:380 [] SYSC_bind+0x129/0x5f0 net/socket.c:1356 [] SyS_bind+0x82/0xa0 net/socket.c:1356 [] do_syscall_64+0x58/0x70 arch/x86/entry/common.c:292 [] return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.o:? origin description: ----address@SYSC_bind (origin=00000000b8c00900) ================================================================== (the line numbers are relative to 4.8-rc6, but the bug persists upstream) , when I run the following program as root: ======================================================= #include #include #include int main(int argc, char *argv[]) { struct sockaddr addr; int size = 0; if (argc > 1) { size = atoi(argv[1]); } memset(&addr, 0, sizeof(addr)); int fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP); bind(fd, &addr, size); return 0; } ======================================================= (for different values of |size| other error reports are printed). This happens because bind() unconditionally copies |size| bytes of |addr| to the kernel, leaving the rest uninitialized. Then security_socket_bind() reads the IP address bytes, including the uninitialized ones, to determine the port, or e.g. pass them further to sel_netnode_find(), which uses them to calculate a hash. Signed-off-by: Alexander Potapenko Acked-by: Eric Dumazet [PM: fixed some whitespace damage] Signed-off-by: Paul Moore Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

selinux: skip bounded transition processing if the policy isn't loaded

2018-02-25T10:05:42+00:00

commit 4b14752ec4e0d87126e636384cf37c8dd9df157c upstream. We can't do anything reasonable in security_bounded_transition() if we don't have a policy loaded, and in fact we could run into problems with some of the code inside expecting a policy. Fix these problems like we do many others in security/selinux/ss/services.c by checking to see if the policy is loaded (ss_initialized) and returning quickly if it isn't. Reported-by: syzbot Signed-off-by: Paul Moore Acked-by: Stephen Smalley Reviewed-by: James Morris Signed-off-by: Greg Kroah-Hartman

selinux: ensure the context is NUL terminated in security_context_to_sid_core()

2018-02-25T10:05:41+00:00

commit ef28df55ac27e1e5cd122e19fa311d886d47a756 upstream. The syzbot/syzkaller automated tests found a problem in security_context_to_sid_core() during early boot (before we load the SELinux policy) where we could potentially feed context strings without NUL terminators into the strcmp() function. We already guard against this during normal operation (after the SELinux policy has been loaded) by making a copy of the context strings and explicitly adding a NUL terminator to the end. The patch extends this protection to the early boot case (no loaded policy) by moving the context copy earlier in security_context_to_sid_core(). Reported-by: syzbot Signed-off-by: Paul Moore Reviewed-By: William Roberts Signed-off-by: Greg Kroah-Hartman

selinux: fix off-by-one in setprocattr

2017-02-14T23:25:34+00:00

commit 0c461cb727d146c9ef2d3e86214f498b78b7d125 upstream. SELinux tries to support setting/clearing of /proc/pid/attr attributes from the shell by ignoring terminating newlines and treating an attribute value that begins with a NUL or newline as an attempt to clear the attribute. However, the test for clearing attributes has always been wrong; it has an off-by-one error, and this could further lead to reading past the end of the allocated buffer since commit bb646cdb12e75d82258c2f2e7746d5952d3e321a ("proc_pid_attr_write(): switch to memdup_user()"). Fix the off-by-one error. Even with this fix, setting and clearing /proc/pid/attr attributes from the shell is not straightforward since the interface does not support multiple write() calls (so shells that write the value and newline separately will set and then immediately clear the attribute, requiring use of echo -n to set the attribute), whereas trying to use echo -n "" to clear the attribute causes the shell to skip the write() call altogether since POSIX says that a zero-length write causes no side effects. Thus, one must use echo -n to set and echo without -n to clear, as in the following example: $ echo -n unconfined_u:object_r:user_home_t:s0 > /proc/$$/attr/fscreate $ cat /proc/$$/attr/fscreate unconfined_u:object_r:user_home_t:s0 $ echo "" > /proc/$$/attr/fscreate $ cat /proc/$$/attr/fscreate Note the use of /proc/$$ rather than /proc/self, as otherwise the cat command will read its own attribute value, not that of the shell. There are no users of this facility to my knowledge; possibly we should just get rid of it. UPDATE: Upon further investigation it appears that a local process with the process:setfscreate permission can cause a kernel panic as a result of this bug. This patch fixes CVE-2017-2618. Signed-off-by: Stephen Smalley [PM: added the update about CVE-2017-2618 to the commit description] Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman Signed-off-by: James Morris

mm: Change vm_is_stack_for_task() to vm_is_stack_for_current()

2016-10-20T07:21:41+00:00

Asking for a non-current task's stack can't be done without races unless the task is frozen in kernel mode. As far as I know, vm_is_stack_for_task() never had a safe non-current use case. The __unused annotation is because some KSTK_ESP implementations ignore their parameter, which IMO is further justification for this patch. Signed-off-by: Andy Lutomirski Acked-by: Thomas Gleixner Cc: Al Viro Cc: Andrew Morton Cc: Borislav Petkov Cc: Brian Gerst Cc: Jann Horn Cc: Kees Cook Cc: Linus Torvalds Cc: Linux API Cc: Peter Zijlstra Cc: Tycho Andersen Link: http://lkml.kernel.org/r/4c3f68f426e6c061ca98b4fc7ef85ffbb0a25b0c.1475257877.git.luto@kernel.org Signed-off-by: Ingo Molnar

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-10-11T03:16:43+00:00

Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning

Merge branch 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-10-11T00:11:50+00:00

Pull vfs xattr updates from Al Viro: "xattr stuff from Andreas This completes the switch to xattr_handler ->get()/->set() from ->getxattr/->setxattr/->removexattr" * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Remove {get,set,remove}xattr inode operations xattr: Stop calling {get,set,remove}xattr inode operations vfs: Check for the IOP_XATTR flag in listxattr xattr: Add __vfs_{get,set,remove}xattr helpers libfs: Use IOP_XATTR flag for empty directory handling vfs: Use IOP_XATTR flag for bad-inode handling vfs: Add IOP_XATTR inode operations flag vfs: Move xattr_resolve_name to the front of fs/xattr.c ecryptfs: Switch to generic xattr handlers sockfs: Get rid of getxattr iop sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names kernfs: Switch to generic xattr handlers hfs: Switch to generic xattr handlers jffs2: Remove jffs2_{get,set,remove}xattr macros xattr: Remove unnecessary NULL attribute name check