kernel/linux.git/lib, branch v3.18.62

lib/cmdline.c: fix get_options() overflow while parsing ranges

2017-06-29T07:12:23+00:00

commit a91e0f680bcd9e10c253ae8b62462a38bd48f09f upstream. When using get_options() it's possible to specify a range of numbers, like 1-100500. The problem is that it doesn't track array size while calling internally to get_range() which iterates over the range and fills the memory with numbers. Link: http://lkml.kernel.org/r/2613C75C-B04D-4BFF-82A6-12F97BA0F620@gmail.com Signed-off-by: Ilya V. Matveychikov Cc: Jonathan Corbet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

usercopy: Adjust tests to deal with SMAP/PAN

2017-06-14T10:54:20+00:00

commit f5f893c57e37ca730808cb2eee3820abd05e7507 upstream. Under SMAP/PAN/etc, we cannot write directly to userspace memory, so this rearranges the test bytes to get written through copy_to_user(). Additionally drops the bad copy_from_user() test that would trigger a memcpy() against userspace on failure. [arnd: the test module was added in 3.14, and this backported patch should apply cleanly on all version from 3.14 to 4.10. The original patch was in 4.11 on top of a context change I saw the bug triggered with kselftest on a 4.4.y stable kernel] Signed-off-by: Kees Cook Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

KEYS: Fix ASN.1 indefinite length object parsing

2017-05-20T12:18:43+00:00

commit 23c8a812dc3c621009e4f0e5342aa4e2ede1ceaa upstream. This fixes CVE-2016-0758. In the ASN.1 decoder, when the length field of an ASN.1 value is extracted, it isn't validated against the remaining amount of data before being added to the cursor. With a sufficiently large size indicated, the check: datalen - dp < 2 may then fail due to integer overflow. Fix this by checking the length indicated against the amount of remaining data in both places a definite length is determined. Whilst we're at it, make the following changes: (1) Check the maximum size of extended length does not exceed the capacity of the variable it's being stored in (len) rather than the type that variable is assumed to be (size_t). (2) Compare the EOC tag to the symbolic constant ASN1_EOC rather than the integer 0. (3) To reduce confusion, move the initialisation of len outside of: for (len = 0; n > 0; n--) { since it doesn't have anything to do with the loop counter n. Signed-off-by: David Howells Reviewed-by: Mimi Zohar Acked-by: David Woodhouse Acked-by: Peter Jones Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

ASN.1: Fix non-match detection failure on data overrun

2017-05-20T12:18:43+00:00

commit 0d62e9dd6da45bbf0f33a8617afc5fe774c8f45f upstream. If the ASN.1 decoder is asked to parse a sequence of objects, non-optional matches get skipped if there's no more data to be had rather than a data-overrun error being reported. This is due to the code segment that decides whether to skip optional matches (ie. matches that could get ignored because an element is marked OPTIONAL in the grammar) due to a lack of data also skips non-optional elements if the data pointer has reached the end of the buffer. This can be tested with the data decoder for the new RSA akcipher algorithm that takes three non-optional integers. Currently, it skips the last integer if there is insufficient data. Without the fix, #defining DEBUG in asn1_decoder.c will show something like: next_op: pc=0/13 dp=0/270 C=0 J=0 - match? 30 30 00 - TAG: 30 266 CONS next_op: pc=2/13 dp=4/270 C=1 J=0 - match? 02 02 00 - TAG: 02 257 - LEAF: 257 next_op: pc=5/13 dp=265/270 C=1 J=0 - match? 02 02 00 - TAG: 02 3 - LEAF: 3 next_op: pc=8/13 dp=270/270 C=1 J=0 next_op: pc=11/13 dp=270/270 C=1 J=0 - end cons t=4 dp=270 l=270/270 The next_op line for pc=8/13 should be followed by a match line. This is not exploitable for X.509 certificates by means of shortening the message and fixing up the ASN.1 CONS tags because: (1) The relevant records being built up are cleared before use. (2) If the message is shortened sufficiently to remove the public key, the ASN.1 parse of the RSA key will fail quickly due to a lack of data. (3) Extracted signature data is either turned into MPIs (which cope with a 0 length) or is simpler integers specifying algoritms and suchlike (which can validly be 0); and (4) The AKID and SKID extensions are optional and their removal is handled without risking passing a NULL to asymmetric_key_generate_id(). (5) If the certificate is truncated sufficiently to remove the subject, issuer or serialNumber then the ASN.1 decoder will fail with a 'Cons stack underflow' return. This is not exploitable for PKCS#7 messages by means of removal of elements from such a message from the tail end of a sequence: (1) Any shortened X.509 certs embedded in the PKCS#7 message are survivable as detailed above. (2) The message digest content isn't used if it shows a NULL pointer, similarly, the authattrs aren't used if that shows a NULL pointer. (3) A missing signature results in a NULL MPI - which the MPI routines deal with. (4) If data is NULL, it is expected that the message has detached content and that is handled appropriately. (5) If the serialNumber is excised, the unconditional action associated with it will pick up the containing SEQUENCE instead, so no NULL pointer will be seen here. If both the issuer and the serialNumber are excised, the ASN.1 decode will fail with an 'Unexpected tag' return. In either case, there's no way to get to asymmetric_key_generate_id() with a NULL pointer. (6) Other fields are decoded to simple integers. Shortening the message to omit an algorithm ID field will cause checks on this to fail early in the verification process. This can also be tested by snipping objects off of the end of the ASN.1 stream such that mandatory tags are removed - or even from the end of internal SEQUENCEs. If any mandatory tag is missing, the error EBADMSG *should* be produced. Without this patch ERANGE or ENOPKG might be produced or the parse may apparently succeed, perhaps with ENOKEY or EKEYREJECTED being produced later, depending on what gets snipped. Just snipping off the final BIT_STRING or OCTET_STRING from either sample should be a start since both are mandatory and neither will cause an EBADMSG without the patches Reported-by: Marcel Holtmann Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: David Woodhouse Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman

cpumask_set_cpu_local_first => cpumask_local_spread, lament

2017-05-08T05:44:12+00:00

commit f36963c9d3f6f415732710da3acdd8608a9fa0e5 upstream. da91309e0a7e (cpumask: Utility function to set n'th cpu...) created a genuinely weird function. I never saw it before, it went through DaveM. (He only does this to make us other maintainers feel better about our own mistakes.) cpumask_set_cpu_local_first's purpose is say "I need to spread things across N online cpus, choose the ones on this numa node first"; you call it in a loop. It can fail. One of the two callers ignores this, the other aborts and fails the device open. It can fail in two ways: allocating the off-stack cpumask, or through a convoluted codepath which AFAICT can only occur if cpu_online_mask changes. Which shouldn't happen, because if cpu_online_mask can change while you call this, it could return a now-offline cpu anyway. It contains a nonsensical test "!cpumask_of_node(numa_node)". This was drawn to my attention by Geert, who said this causes a warning on Sparc. It sets a single bit in a cpumask instead of returning a cpu number, because that's what the callers want. It could be made more efficient by passing the previous cpu rather than an index, but that would be more invasive to the callers. [backporting for 3.18: only two callers exist, otherwise no change. The same warning shows up for "!cpumask_of_node()", and I thought about just addressing the warning, but using the whole fix seemed better in the end as one of the two callers also lacks the error handling] Fixes: da91309e0a7e8966d916a74cce42ed170fde06bf Signed-off-by: Rusty Russell (then rebased) Tested-by: Amir Vadai Acked-by: Amir Vadai Acked-by: David S. Miller Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

lib/vsprintf.c: improve sanity check in vsnprintf()

2017-04-18T05:55:48+00:00

commit 2aa2f9e21e4eb25c720b2e7d80f8929638f6ad73 upstream. On 64 bit, size may very well be huge even if bit 31 happens to be 0. Somehow it doesn't feel right that one can pass a 5 GiB buffer but not a 3 GiB one. So cap at INT_MAX as was probably the intention all along. This is also the made-up value passed by sprintf and vsprintf. Signed-off-by: Rasmus Villemoes Cc: Jiri Kosina Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

dcache: let the dentry count go down to zero without taking d_lock

2016-08-22T16:23:17+00:00

[ Upstream commit 360f54796ed65939093ae373b92ebd5ef3341776 ] We can be more aggressive about this, if we are clever and careful. This is subtle. Signed-off-by: Linus Torvalds Signed-off-by: Al Viro Signed-off-by: Sasha Levin

dma-debug: avoid spinlock recursion when disabling dma-debug

2016-06-06T23:11:13+00:00

[ Upstream commit 3017cd63f26fc655d56875aaf497153ba60e9edf ] With netconsole (at least) the pr_err("... disablingn") call can recurse back into the dma-debug code, where it'll try to grab free_entries_lock again. Avoid the problem by doing the printk after dropping the lock. Link: http://lkml.kernel.org/r/1463678421-18683-1-git-send-email-ville.syrjala@linux.intel.com Signed-off-by: Ville Syrjälä Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

lib: lz4: fixed zram with lz4 on big endian machines

2016-04-20T13:41:02+00:00

[ Upstream commit 3e26a691fe3fe1e02a76e5bab0c143ace4b137b4 ] Based on Sergey's test patch [1], this fixes zram with lz4 compression on big endian cpus. Note that the 64-bit preprocessor test is not a cleanup, it's part of the fix, since those identifiers are bogus (for example, __ppc64__ isn't defined anywhere else in the kernel, which means we'd fall into the 32-bit definitions on ppc64). Tested on ppc64 with no regression on x86_64. [1] http://marc.info/?l=linux-kernel&m=145994470805853&w=4 Cc: stable@vger.kernel.org Suggested-by: Sergey Senozhatsky Signed-off-by: Rui Salvaterra Reviewed-by: Sergey Senozhatsky Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

assoc_array: don't call compare_object() on a node

2016-04-20T13:40:52+00:00

[ Upstream commit 8d4a2ec1e0b41b0cf9a0c5cd4511da7f8e4f3de2 ] Changes since V1: fixed the description and added KASan warning. In assoc_array_insert_into_terminal_node(), we call the compare_object() method on all non-empty slots, even when they're not leaves, passing a pointer to an unexpected structure to compare_object(). Currently it causes an out-of-bound read access in keyring_compare_object detected by KASan (see below). The issue is easily reproduced with keyutils testsuite. Only call compare_object() when the slot is a leave. KASan warning: ================================================================== BUG: KASAN: slab-out-of-bounds in keyring_compare_object+0x213/0x240 at addr ffff880060a6f838 Read of size 8 by task keyctl/1655 ============================================================================= BUG kmalloc-192 (Not tainted): kasan: bad access detected ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in assoc_array_insert+0xfd0/0x3a60 age=69 cpu=1 pid=1647 ___slab_alloc+0x563/0x5c0 __slab_alloc+0x51/0x90 kmem_cache_alloc_trace+0x263/0x300 assoc_array_insert+0xfd0/0x3a60 __key_link_begin+0xfc/0x270 key_create_or_update+0x459/0xaf0 SyS_add_key+0x1ba/0x350 entry_SYSCALL_64_fastpath+0x12/0x76 INFO: Slab 0xffffea0001829b80 objects=16 used=8 fp=0xffff880060a6f550 flags=0x3fff8000004080 INFO: Object 0xffff880060a6f740 @offset=5952 fp=0xffff880060a6e5d1 Bytes b4 ffff880060a6f730: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f740: d1 e5 a6 60 00 88 ff ff 0e 00 00 00 00 00 00 00 ...`............ Object ffff880060a6f750: 02 cf 8e 60 00 88 ff ff 02 c0 8e 60 00 88 ff ff ...`.......`.... Object ffff880060a6f760: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f770: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f790: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f7a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f7b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f7c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f7d0: 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f7e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ Object ffff880060a6f7f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ CPU: 0 PID: 1655 Comm: keyctl Tainted: G B 4.5.0-rc4-kasan+ #291 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000000 000000001b2800b4 ffff880060a179e0 ffffffff81b60491 ffff88006c802900 ffff880060a6f740 ffff880060a17a10 ffffffff815e2969 ffff88006c802900 ffffea0001829b80 ffff880060a6f740 ffff880060a6e650 Call Trace: [] dump_stack+0x85/0xc4 [] print_trailer+0xf9/0x150 [] object_err+0x34/0x40 [] kasan_report_error+0x230/0x550 [] ? keyring_get_key_chunk+0x13e/0x210 [] __asan_report_load_n_noabort+0x5d/0x70 [] ? keyring_compare_object+0x213/0x240 [] keyring_compare_object+0x213/0x240 [] assoc_array_insert+0x86c/0x3a60 [] ? assoc_array_cancel_edit+0x70/0x70 [] ? __key_link_begin+0x20d/0x270 [] __key_link_begin+0xfc/0x270 [] key_create_or_update+0x459/0xaf0 [] ? trace_hardirqs_on+0xd/0x10 [] ? key_type_lookup+0xc0/0xc0 [] ? lookup_user_key+0x13d/0xcd0 [] ? memdup_user+0x53/0x80 [] SyS_add_key+0x1ba/0x350 [] ? key_get_type_from_user.constprop.6+0xa0/0xa0 [] ? retint_user+0x18/0x23 [] ? trace_hardirqs_on_caller+0x3fe/0x580 [] ? trace_hardirqs_on_thunk+0x17/0x19 [] entry_SYSCALL_64_fastpath+0x12/0x76 Memory state around the buggy address: ffff880060a6f700: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff880060a6f780: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc >ffff880060a6f800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff880060a6f880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff880060a6f900: fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 ================================================================== Signed-off-by: Jerome Marchand Signed-off-by: David Howells cc: stable@vger.kernel.org Signed-off-by: Sasha Levin