kernel/linux.git/lib, branch v3.12.62

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

2016-06-15T07:32:17+00:00

commit 3017cd63f26fc655d56875aaf497153ba60e9edf upstream. 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby

KEYS: Fix ASN.1 indefinite length object parsing

2016-05-19T09:00:14+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: Jiri Slaby

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

2016-05-19T09:00:13+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: Jiri Slaby

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

2016-05-02T17:54:56+00:00

commit 3e26a691fe3fe1e02a76e5bab0c143ace4b137b4 upstream. 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 Suggested-by: Sergey Senozhatsky Signed-off-by: Rui Salvaterra Reviewed-by: Sergey Senozhatsky Signed-off-by: Jiri Slaby

lib/ucs2_string: Correct ucs2 -> utf8 conversion

2016-03-14T22:10:36+00:00

commit a68075908a37850918ad96b056acc9ac4ce1bd90 upstream. The comparisons should be >= since 0x800 and 0x80 require an additional bit to store. For the 3 byte case, the existing shift would drop off 2 more bits than intended. For the 2 byte case, there should be 5 bits bits in byte 1, and 6 bits in byte 2. Signed-off-by: Jason Andryuk Reviewed-by: Laszlo Ersek Cc: Peter Jones Cc: Matthew Garrett Cc: "Lee, Chun-Yi" Signed-off-by: Matt Fleming Signed-off-by: Jiri Slaby

lib/ucs2_string: Add ucs2 -> utf8 helper functions

2016-03-14T22:10:32+00:00

commit 73500267c930baadadb0d02284909731baf151f7 upstream. This adds ucs2_utf8size(), which tells us how big our ucs2 string is in bytes, and ucs2_as_utf8, which translates from ucs2 to utf8.. Signed-off-by: Peter Jones Tested-by: Lee, Chun-Yi Acked-by: Matthew Garrett Signed-off-by: Matt Fleming Signed-off-by: Jiri Slaby

devres: fix a for loop bounds check

2016-03-03T11:45:55+00:00

commit 1f35d04a02a652f14566f875aef3a6f2af4cb77b upstream. The iomap[] array has PCIM_IOMAP_MAX (6) elements and not DEVICE_COUNT_RESOURCE (16). This bug was found using a static checker. It may be that the "if (!(mask & (1 << i)))" check means we never actually go past the end of the array in real life. Fixes: ec04b075843d ('iomap: implement pcim_iounmap_regions()') Signed-off-by: Dan Carpenter Acked-by: Tejun Heo Signed-off-by: Jiri Slaby Signed-off-by: Jiri Slaby

dump_stack: avoid potential deadlocks

2016-02-25T09:49:17+00:00

commit d7ce36924344ace0dbdc855b1206cacc46b36d45 upstream. Some servers experienced fatal deadlocks because of a combination of bugs, leading to multiple cpus calling dump_stack(). The checksumming bug was fixed in commit 34ae6a1aa054 ("ipv6: update skb->csum when CE mark is propagated"). The second problem is a faulty locking in dump_stack() CPU1 runs in process context and calls dump_stack(), grabs dump_lock. CPU2 receives a TCP packet under softirq, grabs socket spinlock, and call dump_stack() from netdev_rx_csum_fault(). dump_stack() spins on atomic_cmpxchg(&dump_lock, -1, 2), since dump_lock is owned by CPU1 While dumping its stack, CPU1 is interrupted by a softirq, and happens to process a packet for the TCP socket locked by CPU2. CPU1 spins forever in spin_lock() : deadlock Stack trace on CPU1 looked like : NMI backtrace for cpu 1 RIP: _raw_spin_lock+0x25/0x30 ... Call Trace: tcp_v6_rcv+0x243/0x620 ip6_input_finish+0x11f/0x330 ip6_input+0x38/0x40 ip6_rcv_finish+0x3c/0x90 ipv6_rcv+0x2a9/0x500 process_backlog+0x461/0xaa0 net_rx_action+0x147/0x430 __do_softirq+0x167/0x2d0 call_softirq+0x1c/0x30 do_softirq+0x3f/0x80 irq_exit+0x6e/0xc0 smp_call_function_single_interrupt+0x35/0x40 call_function_single_interrupt+0x6a/0x70 printk+0x4d/0x4f printk_address+0x31/0x33 print_trace_address+0x33/0x3c print_context_stack+0x7f/0x119 dump_trace+0x26b/0x28e show_trace_log_lvl+0x4f/0x5c show_stack_log_lvl+0x104/0x113 show_stack+0x42/0x44 dump_stack+0x46/0x58 netdev_rx_csum_fault+0x38/0x3c __skb_checksum_complete_head+0x6e/0x80 __skb_checksum_complete+0x11/0x20 tcp_rcv_established+0x2bd5/0x2fd0 tcp_v6_do_rcv+0x13c/0x620 sk_backlog_rcv+0x15/0x30 release_sock+0xd2/0x150 tcp_recvmsg+0x1c1/0xfc0 inet_recvmsg+0x7d/0x90 sock_recvmsg+0xaf/0xe0 ___sys_recvmsg+0x111/0x3b0 SyS_recvmsg+0x5c/0xb0 system_call_fastpath+0x16/0x1b Fixes: b58d977432c8 ("dump_stack: serialize the output from dump_stack()") Signed-off-by: Eric Dumazet Cc: Alex Thorlton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby

radix-tree: fix race in gang lookup

2016-02-25T09:49:15+00:00

commit 46437f9a554fbe3e110580ca08ab703b59f2f95a upstream. If the indirect_ptr bit is set on a slot, that indicates we need to redo the lookup. Introduce a new function radix_tree_iter_retry() which forces the loop to retry the lookup by setting 'slot' to NULL and turning the iterator back to point at the problematic entry. This is a pretty rare problem to hit at the moment; the lookup has to race with a grow of the radix tree from a height of 0. The consequences of hitting this race are that gang lookup could return a pointer to a radix_tree_node instead of a pointer to whatever the user had inserted in the tree. Fixes: cebbd29e1c2f ("radix-tree: rewrite gang lookup using iterator") Signed-off-by: Matthew Wilcox Cc: Hugh Dickins Cc: Ohad Ben-Cohen Cc: Konstantin Khlebnikov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby

dma-debug: switch check from _text to _stext

2016-02-25T09:49:14+00:00

commit ea535e418c01837d07b6c94e817540f50bfdadb0 upstream. In include/asm-generic/sections.h: /* * Usage guidelines: * _text, _data: architecture specific, don't use them in * arch-independent code * [_stext, _etext]: contains .text.* sections, may also contain * .rodata.* * and/or .init.* sections _text is not guaranteed across architectures. Architectures such as ARM may reuse parts which are not actually text and erroneously trigger a bug. Switch to using _stext which is guaranteed to contain text sections. Came out of https://lkml.kernel.org/g/<567B1176.4000106@redhat.com> Signed-off-by: Laura Abbott Reviewed-by: Kees Cook Cc: Russell King Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby