kernel/linux.git/lib, branch v3.14.43

lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR

2015-05-06T19:59:20+00:00

commit 0b053c9518292705736329a8fe20ef4686ffc8e9 upstream. OPTIMIZER_HIDE_VAR(), as defined when using gcc, is insufficient to ensure protection from dead store optimization. For the random driver and crypto drivers, calls are emitted ... $ gdb vmlinux (gdb) disassemble memzero_explicit Dump of assembler code for function memzero_explicit: 0xffffffff813a18b0 <+0>: push %rbp 0xffffffff813a18b1 <+1>: mov %rsi,%rdx 0xffffffff813a18b4 <+4>: xor %esi,%esi 0xffffffff813a18b6 <+6>: mov %rsp,%rbp 0xffffffff813a18b9 <+9>: callq 0xffffffff813a7120 0xffffffff813a18be <+14>: pop %rbp 0xffffffff813a18bf <+15>: retq End of assembler dump. (gdb) disassemble extract_entropy [...] 0xffffffff814a5009 <+313>: mov %r12,%rdi 0xffffffff814a500c <+316>: mov $0xa,%esi 0xffffffff814a5011 <+321>: callq 0xffffffff813a18b0 0xffffffff814a5016 <+326>: mov -0x48(%rbp),%rax [...] ... but in case in future we might use facilities such as LTO, then OPTIMIZER_HIDE_VAR() is not sufficient to protect gcc from a possible eviction of the memset(). We have to use a compiler barrier instead. Minimal test example when we assume memzero_explicit() would *not* be a call, but would have been *inlined* instead: static inline void memzero_explicit(void *s, size_t count) { memset(s, 0, count); } int main(void) { char buff[20]; snprintf(buff, sizeof(buff) - 1, "test"); printf("%s", buff); memzero_explicit(buff, sizeof(buff)); return 0; } With := OPTIMIZER_HIDE_VAR(): (gdb) disassemble main Dump of assembler code for function main: [...] 0x0000000000400464 <+36>: callq 0x400410 0x0000000000400469 <+41>: xor %eax,%eax 0x000000000040046b <+43>: add $0x28,%rsp 0x000000000040046f <+47>: retq End of assembler dump. With := barrier(): (gdb) disassemble main Dump of assembler code for function main: [...] 0x0000000000400464 <+36>: callq 0x400410 0x0000000000400469 <+41>: movq $0x0,(%rsp) 0x0000000000400471 <+49>: movq $0x0,0x8(%rsp) 0x000000000040047a <+58>: movl $0x0,0x10(%rsp) 0x0000000000400482 <+66>: xor %eax,%eax 0x0000000000400484 <+68>: add $0x28,%rsp 0x0000000000400488 <+72>: retq End of assembler dump. As can be seen, movq, movq, movl are being emitted inlined via memset(). Reference: http://thread.gmane.org/gmane.linux.kernel.cryptoapi/13764/ Fixes: d4c5efdb9777 ("random: add and use memzero_explicit() for clearing data") Cc: Theodore Ts'o Signed-off-by: mancha security Signed-off-by: Daniel Borkmann Acked-by: Hannes Frederic Sowa Acked-by: Stephan Mueller Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

LZ4 : fix the data abort issue

2015-03-26T14:06:52+00:00

commit d5e7cafd69da24e6d6cc988fab6ea313a2577efc upstream. If the part of the compression data are corrupted, or the compression data is totally fake, the memory access over the limit is possible. This is the log from my system usning lz4 decompression. [6502]data abort, halting [6503]r0 0x00000000 r1 0x00000000 r2 0xdcea0ffc r3 0xdcea0ffc [6509]r4 0xb9ab0bfd r5 0xdcea0ffc r6 0xdcea0ff8 r7 0xdce80000 [6515]r8 0x00000000 r9 0x00000000 r10 0x00000000 r11 0xb9a98000 [6522]r12 0xdcea1000 usp 0x00000000 ulr 0x00000000 pc 0x820149bc [6528]spsr 0x400001f3 and the memory addresses of some variables at the moment are ref:0xdcea0ffc, op:0xdcea0ffc, oend:0xdcea1000 As you can see, COPYLENGH is 8bytes, so @ref and @op can access the momory over @oend. Signed-off-by: JeHyeon Yeon Reviewed-by: David Sterba Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

lib/checksum.c: fix build for generic csum_tcpudp_nofold

2015-02-11T06:54:48+00:00

commit 9ce357795ef208faa0d59894d9d119a7434e37f3 upstream. Fixed commit added from64to32 under _#ifndef do_csum_ but used it under _#ifndef csum_tcpudp_nofold_, breaking some builds (Fengguang's robot reported TILEGX's). Move from64to32 under the latter. Fixes: 150ae0e94634 ("lib/checksum.c: fix carry in csum_tcpudp_nofold") Reported-by: kbuild test robot Signed-off-by: Karl Beldan Cc: Eric Dumazet Cc: David S. Miller Signed-off-by: David S. Miller Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

lib/checksum.c: fix carry in csum_tcpudp_nofold

2015-02-11T06:54:47+00:00

commit 150ae0e94634714b23919f0c333fee28a5b199d5 upstream. The carry from the 64->32bits folding was dropped, e.g with: saddr=0xFFFFFFFF daddr=0xFF0000FF len=0xFFFF proto=0 sum=1, csum_tcpudp_nofold returned 0 instead of 1. Signed-off-by: Karl Beldan Cc: Al Viro Cc: Eric Dumazet Cc: Arnd Bergmann Cc: Mike Frysinger Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

decompress_bunzip2: off by one in get_next_block()

2015-01-27T16:18:58+00:00

commit b5c8afe5be51078a979d86ae5ae78c4ac948063d upstream. "origPtr" is used as an offset into the bd->dbuf[] array. That array is allocated in start_bunzip() and has "bd->dbufSize" number of elements so the test here should be >= instead of >. Later we check "origPtr" again before using it as an offset so I don't know if this bug can be triggered in real life. Fixes: bc22c17e12c1 ('bzip2/lzma: library support for gzip, bzip2 and lzma decompression') Signed-off-by: Dan Carpenter Cc: Alain Knaff Cc: Yinghai Lu Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm: filemap: move radix tree hole searching here

2014-11-21T17:23:06+00:00

commit e7b563bb2a6f4d974208da46200784b9c5b5a47e upstream. The radix tree hole searching code is only used for page cache, for example the readahead code trying to get a a picture of the area surrounding a fault. It sufficed to rely on the radix tree definition of holes, which is "empty tree slot". But this is about to change, though, as shadow page descriptors will be stored in the page cache after the actual pages get evicted from memory. Move the functions over to mm/filemap.c and make them native page cache operations, where they can later be adapted to handle the new definition of "page cache hole". Signed-off-by: Johannes Weiner Reviewed-by: Rik van Riel Reviewed-by: Minchan Kim Acked-by: Mel Gorman Cc: Andrea Arcangeli Cc: Bob Liu Cc: Christoph Hellwig Cc: Dave Chinner Cc: Greg Thelen Cc: Hugh Dickins Cc: Jan Kara Cc: KOSAKI Motohiro Cc: Luigi Semenzato Cc: Metin Doslu Cc: Michel Lespinasse Cc: Ozgun Erdogan Cc: Peter Zijlstra Cc: Roman Gushchin Cc: Ryan Mallon Cc: Tejun Heo Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman Signed-off-by: Greg Kroah-Hartman

lib: radix-tree: add radix_tree_delete_item()

2014-11-21T17:23:06+00:00

commit 53c59f262d747ea82e7414774c59a489501186a0 upstream. Provide a function that does not just delete an entry at a given index, but also allows passing in an expected item. Delete only if that item is still located at the specified index. This is handy when lockless tree traversals want to delete entries as well because they don't have to do an second, locked lookup to verify the slot has not changed under them before deleting the entry. Signed-off-by: Johannes Weiner Reviewed-by: Minchan Kim Reviewed-by: Rik van Riel Acked-by: Mel Gorman Cc: Andrea Arcangeli Cc: Bob Liu Cc: Christoph Hellwig Cc: Dave Chinner Cc: Greg Thelen Cc: Hugh Dickins Cc: Jan Kara Cc: KOSAKI Motohiro Cc: Luigi Semenzato Cc: Metin Doslu Cc: Michel Lespinasse Cc: Ozgun Erdogan Cc: Peter Zijlstra Cc: Roman Gushchin Cc: Ryan Mallon Cc: Tejun Heo Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman Signed-off-by: Greg Kroah-Hartman

lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}()

2014-11-14T17:00:08+00:00

commit ea5d05b34aca25c066e0699512d0ffbd8ee6ac3e upstream. If __bitmap_shift_left() or __bitmap_shift_right() are asked to shift by a multiple of BITS_PER_LONG, they will try to shift a long value by BITS_PER_LONG bits which is undefined. Change the functions to avoid the undefined shift. Coverity id: 1192175 Coverity id: 1192174 Signed-off-by: Jan Kara Cc: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

random: add and use memzero_explicit() for clearing data

2014-11-14T16:59:49+00:00

commit d4c5efdb97773f59a2b711754ca0953f24516739 upstream. zatimend has reported that in his environment (3.16/gcc4.8.3/corei7) memset() calls which clear out sensitive data in extract_{buf,entropy, entropy_user}() in random driver are being optimized away by gcc. Add a helper memzero_explicit() (similarly as explicit_bzero() variants) that can be used in such cases where a variable with sensitive data is being cleared out in the end. Other use cases might also be in crypto code. [ I have put this into lib/string.c though, as it's always built-in and doesn't need any dependencies then. ] Fixes kernel bugzilla: 82041 Reported-by: zatimend@hotmail.co.uk Signed-off-by: Daniel Borkmann Acked-by: Hannes Frederic Sowa Cc: Alexey Dobriyan Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

lzo: check for length overrun in variable length encoding.

2014-10-30T16:38:22+00:00

commit 72cf90124e87d975d0b2114d930808c58b4c05e4 upstream. This fix ensures that we never meet an integer overflow while adding 255 while parsing a variable length encoding. It works differently from commit 206a81c ("lzo: properly check for overruns") because instead of ensuring that we don't overrun the input, which is tricky to guarantee due to many assumptions in the code, it simply checks that the cumulated number of 255 read cannot overflow by bounding this number. The MAX_255_COUNT is the maximum number of times we can add 255 to a base count without overflowing an integer. The multiply will overflow when multiplying 255 by more than MAXINT/255. The sum will overflow earlier depending on the base count. Since the base count is taken from a u8 and a few bits, it is safe to assume that it will always be lower than or equal to 2*255, thus we can always prevent any overflow by accepting two less 255 steps. This patch also reduces the CPU overhead and actually increases performance by 1.1% compared to the initial code, while the previous fix costs 3.1% (measured on x86_64). The fix needs to be backported to all currently supported stable kernels. Reported-by: Willem Pinckaers Cc: "Don A. Bailey" Signed-off-by: Willy Tarreau Signed-off-by: Greg Kroah-Hartman