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2016-11-25mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]Andrey Ryabinin1-1/+6
This fixes CVE-2016-8650. If mpi_powm() is given a zero exponent, it wants to immediately return either 1 or 0, depending on the modulus. However, if the result was initalised with zero limb space, no limbs space is allocated and a NULL-pointer exception ensues. Fix this by allocating a minimal amount of limb space for the result when the 0-exponent case when the result is 1 and not touching the limb space when the result is 0. This affects the use of RSA keys and X.509 certificates that carry them. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 PGD 0 Oops: 0002 [#1] SMP Modules linked in: CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 task: ffff8804011944c0 task.stack: ffff880401294000 RIP: 0010:[<ffffffff8138ce5d>] [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 RSP: 0018:ffff880401297ad8 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0 RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0 RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000 R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50 FS: 00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0 Stack: ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8 Call Trace: [<ffffffff81376cd4>] ? __sg_page_iter_next+0x43/0x66 [<ffffffff81376d12>] ? sg_miter_get_next_page+0x1b/0x5d [<ffffffff81376f37>] ? sg_miter_next+0x17/0xbd [<ffffffff8138ba3a>] ? mpi_read_raw_from_sgl+0xf2/0x146 [<ffffffff8132a95c>] rsa_verify+0x9d/0xee [<ffffffff8132acca>] ? pkcs1pad_sg_set_buf+0x2e/0xbb [<ffffffff8132af40>] pkcs1pad_verify+0xc0/0xe1 [<ffffffff8133cb5e>] public_key_verify_signature+0x1b0/0x228 [<ffffffff8133d974>] x509_check_for_self_signed+0xa1/0xc4 [<ffffffff8133cdde>] x509_cert_parse+0x167/0x1a1 [<ffffffff8133d609>] x509_key_preparse+0x21/0x1a1 [<ffffffff8133c3d7>] asymmetric_key_preparse+0x34/0x61 [<ffffffff812fc9f3>] key_create_or_update+0x145/0x399 [<ffffffff812fe227>] SyS_add_key+0x154/0x19e [<ffffffff81001c2b>] do_syscall_64+0x80/0x191 [<ffffffff816825e4>] entry_SYSCALL64_slow_path+0x25/0x25 Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce <49> c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f RIP [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 RSP <ffff880401297ad8> CR2: 0000000000000000 ---[ end trace d82015255d4a5d8d ]--- Basically, this is a backport of a libgcrypt patch: http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526 Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files (part 1)") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> cc: linux-ima-devel@lists.sourceforge.net cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-07-29lib/mpi: Fix SG miter leakHerbert Xu1-7/+7
In mpi_read_raw_from_sgl we may leak the SG miter resouces after reading the leading zeroes. This patch fixes this by stopping the iteration once the leading zeroes have been read. Fixes: 127827b9c295 ("lib/mpi: Do not do sg_virt") Reported-by: Nicolai Stange <nicstange@gmail.com> Tested-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-01lib/mpi: Do not do sg_virtHerbert Xu1-36/+50
Currently the mpi SG helpers use sg_virt which is completely broken. It happens to work with normal kernel memory but will fail with anything that is not linearly mapped. This patch fixes this by using the SG iterator helpers. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-07-01crypto: rsa - Generate fixed-length outputHerbert Xu1-29/+26
Every implementation of RSA that we have naturally generates output with leading zeroes. The one and only user of RSA, pkcs1pad wants to have those leading zeroes in place, in fact because they are currently absent it has to write those zeroes itself. So we shouldn't be stripping leading zeroes in the first place. In fact this patch makes rsa-generic produce output with fixed length so that pkcs1pad does not need to do any extra work. This patch also changes DH to use the new interface. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31lib/mpi: refactor mpi_read_from_buffer() in terms of mpi_read_raw_data()Nicolai Stange1-21/+3
mpi_read_from_buffer() and mpi_read_raw_data() do basically the same thing except that the former extracts the number of payload bits from the first two bytes of the input buffer. Besides that, the data copying logic is exactly the same. Replace the open coded buffer to MPI instance conversion by a call to mpi_read_raw_data(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31lib/mpi: mpi_read_from_buffer(): sanitize short buffer printkNicolai Stange1-2/+2
The first two bytes of the input buffer encode its expected length and mpi_read_from_buffer() prints a console message if the given buffer is too short. However, there are some oddities with how this message is printed: - It is printed at the default loglevel. This is different from the one used in the case that the first two bytes' value is unsupportedly large, i.e. KERN_INFO. - The format specifier '%d' is used for unsigned ints. - It prints the values of nread and *ret_nread. This is redundant since the former is always the latter + 1. Clean this up as follows: - Use pr_info() rather than printk() with no loglevel. - Use the format specifiers '%u' in place if '%d'. - Do not print the redundant 'nread' but the more helpful 'nbytes' value. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31lib/mpi: mpi_read_from_buffer(): return -EINVAL upon too short bufferNicolai Stange1-10/+8
Currently, if the input buffer is shorter than the expected length as indicated by its first two bytes, an MPI instance of this expected length will be allocated and filled with as much data as is available. The rest will remain uninitialized. Instead of leaving this condition undetected, an error code should be reported to the caller. Since this situation indicates that the input buffer's first two bytes, encoding the number of expected bits, are garbled, -EINVAL is appropriate here. If the input buffer is shorter than indicated by its first two bytes, make mpi_read_from_buffer() return -EINVAL. Get rid of the 'nread' variable: with the new semantics, the total number of bytes read from the input buffer is known in advance. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31lib/mpi: mpi_read_from_buffer(): return error codeNicolai Stange1-3/+3
mpi_read_from_buffer() reads a MPI from a buffer into a newly allocated MPI instance. It expects the buffer's leading two bytes to contain the number of bits, followed by the actual payload. On failure, it returns NULL and updates the in/out argument ret_nread somewhat inconsistently: - If the given buffer is too short to contain the leading two bytes encoding the number of bits or their value is unsupported, then ret_nread will be cleared. - If the allocation of the resulting MPI instance fails, ret_nread is left as is. The only user of mpi_read_from_buffer(), digsig_verify_rsa(), simply checks for a return value of NULL and returns -ENOMEM if that happens. While this is all of cosmetic nature only, there is another error condition which currently isn't detectable by the caller of mpi_read_from_buffer(): if the given buffer is too small to hold the number of bits as encoded in its first two bytes, the return value will be non-NULL and *ret_nread > 0. In preparation of communicating this condition to the caller, let mpi_read_from_buffer() return error values by means of the ERR_PTR() mechanism. Make the sole caller of mpi_read_from_buffer(), digsig_verify_rsa(), check the return value for IS_ERR() rather than == NULL. If IS_ERR() is true, return the associated error value rather than the fixed -ENOMEM. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31lib/mpi: mpi_read_raw_data(): fix nbits calculationNicolai Stange1-1/+1
The number of bits, nbits, is calculated in mpi_read_raw_data() as follows: nbits = nbytes * 8; Afterwards, the number of leading zero bits of the first byte get subtracted: nbits -= count_leading_zeros(buffer[0]); However, count_leading_zeros() takes an unsigned long and thus, the u8 gets promoted to an unsigned long. Thus, the above doesn't subtract the number of leading zeros in the most significant nonzero input byte from nbits, but the number of leading zeros of the most significant nonzero input byte promoted to unsigned long, i.e. BITS_PER_LONG - 8 too many. Fix this by subtracting count_leading_zeros(...) - (BITS_PER_LONG - 8) from nbits only. Fixes: e1045992949 ("MPILIB: Provide a function to read raw data into an MPI") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31lib/mpi: mpi_read_raw_data(): purge redundant clearing of nbitsNicolai Stange1-2/+0
In mpi_read_raw_data(), unsigned nbits is calculated as follows: nbits = nbytes * 8; and redundantly cleared later on if nbytes == 0: if (nbytes > 0) ... else nbits = 0; Purge this redundant clearing for the sake of clarity. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-31lib/mpi: purge mpi_set_buffer()Nicolai Stange1-76/+0
mpi_set_buffer() has no in-tree users and similar functionality is provided by mpi_read_raw_data(). Remove mpi_set_buffer(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_raw_from_sgl(): fix out-of-bounds buffer accessNicolai Stange1-3/+0
Within the copying loop in mpi_read_raw_from_sgl(), the last input SGE's byte count gets artificially extended as follows: if (sg_is_last(sg) && (len % BYTES_PER_MPI_LIMB)) len += BYTES_PER_MPI_LIMB - (len % BYTES_PER_MPI_LIMB); Within the following byte copying loop, this causes reads beyond that SGE's allocated buffer: BUG: KASAN: slab-out-of-bounds in mpi_read_raw_from_sgl+0x331/0x650 at addr ffff8801e168d4d8 Read of size 1 by task systemd-udevd/721 [...] Call Trace: [<ffffffff818c4d35>] dump_stack+0xbc/0x117 [<ffffffff818c4c79>] ? _atomic_dec_and_lock+0x169/0x169 [<ffffffff814af5d1>] ? print_section+0x61/0xb0 [<ffffffff814b1109>] print_trailer+0x179/0x2c0 [<ffffffff814bc524>] object_err+0x34/0x40 [<ffffffff814bfdc7>] kasan_report_error+0x307/0x8c0 [<ffffffff814bf315>] ? kasan_unpoison_shadow+0x35/0x50 [<ffffffff814bf38e>] ? kasan_kmalloc+0x5e/0x70 [<ffffffff814c0ad1>] kasan_report+0x71/0xa0 [<ffffffff81938171>] ? mpi_read_raw_from_sgl+0x331/0x650 [<ffffffff814bf1a6>] __asan_load1+0x46/0x50 [<ffffffff81938171>] mpi_read_raw_from_sgl+0x331/0x650 [<ffffffff817f41b6>] rsa_verify+0x106/0x260 [<ffffffff817f40b0>] ? rsa_set_pub_key+0xf0/0xf0 [<ffffffff818edc79>] ? sg_init_table+0x29/0x50 [<ffffffff817f4d22>] ? pkcs1pad_sg_set_buf+0xb2/0x2e0 [<ffffffff817f5b74>] pkcs1pad_verify+0x1f4/0x2b0 [<ffffffff81831057>] public_key_verify_signature+0x3a7/0x5e0 [<ffffffff81830cb0>] ? public_key_describe+0x80/0x80 [<ffffffff817830f0>] ? keyring_search_aux+0x150/0x150 [<ffffffff818334a4>] ? x509_request_asymmetric_key+0x114/0x370 [<ffffffff814b83f0>] ? kfree+0x220/0x370 [<ffffffff818312c2>] public_key_verify_signature_2+0x32/0x50 [<ffffffff81830b5c>] verify_signature+0x7c/0xb0 [<ffffffff81835d0c>] pkcs7_validate_trust+0x42c/0x5f0 [<ffffffff813c391a>] system_verify_data+0xca/0x170 [<ffffffff813c3850>] ? top_trace_array+0x9b/0x9b [<ffffffff81510b29>] ? __vfs_read+0x279/0x3d0 [<ffffffff8129372f>] mod_verify_sig+0x1ff/0x290 [...] The exact purpose of the len extension isn't clear to me, but due to its form, I suspect that it's a leftover somehow accounting for leading zero bytes within the most significant output limb. Note however that without that len adjustement, the total number of bytes ever processed by the inner loop equals nbytes and thus, the last output limb gets written at this point. Thus the net effect of the len adjustement cited above is just to keep the inner loop running for some more iterations, namely < BYTES_PER_MPI_LIMB ones, reading some extra bytes from beyond the last SGE's buffer and discarding them afterwards. Fix this issue by purging the extension of len beyond the last input SGE's buffer length. Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_raw_from_sgl(): sanitize meaning of indicesNicolai Stange1-6/+3
Within the byte reading loop in mpi_read_raw_sgl(), there are two housekeeping indices used, z and x. At all times, the index z represents the number of output bytes covered by the input SGEs for which processing has completed so far. This includes any leading zero bytes within the most significant limb. The index x changes its meaning after the first outer loop's iteration though: while processing the first input SGE, it represents "number of leading zero bytes in most significant output limb" + "current position within current SGE" For the remaining SGEs OTOH, x corresponds just to "current position within current SGE" After all, it is only the sum of z and x that has any meaning for the output buffer and thus, the "number of leading zero bytes in most significant output limb" part can be moved away from x into z from the beginning, opening up the opportunity for cleaner code. Before the outer loop iterating over the SGEs, don't initialize z with zero, but with the number of leading zero bytes in the most significant output limb. For the inner loop iterating over a single SGE's bytes, get rid of the buf_shift offset to x' bounds and let x run from zero to sg->length - 1. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_raw_from_sgl(): fix nbits calculationNicolai Stange1-1/+2
The number of bits, nbits, is calculated in mpi_read_raw_from_sgl() as follows: nbits = nbytes * 8; Afterwards, the number of leading zero bits of the first byte get subtracted: nbits -= count_leading_zeros(*(u8 *)(sg_virt(sgl) + lzeros)); However, count_leading_zeros() takes an unsigned long and thus, the u8 gets promoted to an unsigned long. Thus, the above doesn't subtract the number of leading zeros in the most significant nonzero input byte from nbits, but the number of leading zeros of the most significant nonzero input byte promoted to unsigned long, i.e. BITS_PER_LONG - 8 too many. Fix this by subtracting count_leading_zeros(...) - (BITS_PER_LONG - 8) from nbits only. Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_raw_from_sgl(): purge redundant clearing of nbitsNicolai Stange1-2/+0
In mpi_read_raw_from_sgl(), unsigned nbits is calculated as follows: nbits = nbytes * 8; and redundantly cleared later on if nbytes == 0: if (nbytes > 0) ... else nbits = 0; Purge this redundant clearing for the sake of clarity. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_raw_from_sgl(): don't include leading zero SGEs in nbytesNicolai Stange1-6/+2
At the very beginning of mpi_read_raw_from_sgl(), the leading zeros of the input scatterlist are counted: lzeros = 0; for_each_sg(sgl, sg, ents, i) { ... if (/* sg contains nonzero bytes */) break; /* sg contains nothing but zeros here */ ents--; lzeros = 0; } Later on, the total number of trailing nonzero bytes is calculated by subtracting the number of leading zero bytes from the total number of input bytes: nbytes -= lzeros; However, since lzeros gets reset to zero for each completely zero leading sg in the loop above, it doesn't include those. Besides wasting resources by allocating a too large output buffer, this mistake propagates into the calculation of x, the number of leading zeros within the most significant output limb: x = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; What's more, the low order bytes of the output, equal in number to the extra bytes in nbytes, are left uninitialized. Fix this by adjusting nbytes for each completely zero leading scatterlist entry. Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_raw_from_sgl(): replace len argument by nbytesNicolai Stange1-4/+4
Currently, the nbytes local variable is calculated from the len argument as follows: ... mpi_read_raw_from_sgl(..., unsigned int len) { unsigned nbytes; ... if (!ents) nbytes = 0; else nbytes = len - lzeros; ... } Given that nbytes is derived from len in a trivial way and that the len argument is shadowed by a local len variable in several loops, this is just confusing. Rename the len argument to nbytes and get rid of the nbytes local variable. Do the nbytes calculation in place. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_buffer(): fix buffer overflowNicolai Stange1-10/+3
Currently, mpi_read_buffer() writes full limbs to the output buffer and moves memory around to purge leading zero limbs afterwards. However, with commit 9cbe21d8f89d ("lib/mpi: only require buffers as big as needed for the integer") the caller is only required to provide a buffer large enough to hold the result without the leading zeros. This might result in a buffer overflow for small MP numbers with leading zeros. Fix this by coping the result to its final destination within the output buffer and not copying the leading zeros at all. Fixes: 9cbe21d8f89d ("lib/mpi: only require buffers as big as needed for the integer") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_buffer(): replace open coded endian conversionNicolai Stange1-15/+12
Currently, the endian conversion from CPU order to BE is open coded in mpi_read_buffer(). Replace this by the centrally provided cpu_to_be*() macros. Copy from the temporary storage on stack to the destination buffer by means of memcpy(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_read_buffer(): optimize skipping of leading zero limbsNicolai Stange1-10/+8
Currently, if the number of leading zeros is greater than fits into a complete limb, mpi_read_buffer() skips them by iterating over them limb-wise. Instead of skipping the high order zero limbs within the loop as shown above, adjust the copying loop's bounds. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_write_sgl(): replace open coded endian conversionNicolai Stange1-16/+11
Currently, the endian conversion from CPU order to BE is open coded in mpi_write_sgl(). Replace this by the centrally provided cpu_to_be*() macros. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_write_sgl(): fix out-of-bounds stack accessNicolai Stange1-5/+1
Within the copying loop in mpi_write_sgl(), we have if (lzeros) { mpi_limb_t *limb1 = (void *)p - sizeof(alimb); mpi_limb_t *limb2 = (void *)p - sizeof(alimb) + lzeros; *limb1 = *limb2; ... } where p points past the end of alimb2 which lives on the stack and contains the current limb in BE order. The purpose of the above is to shift the non-zero bytes of alimb2 to its beginning in memory, i.e. to skip its leading zero bytes. However, limb2 points somewhere into the middle of alimb2 and thus, reading *limb2 pulls in lzero bytes from somewhere. Indeed, KASAN splats: BUG: KASAN: stack-out-of-bounds in mpi_write_to_sgl+0x4e3/0x6f0 at addr ffff8800cb04f601 Read of size 8 by task systemd-udevd/391 page:ffffea00032c13c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x3fff8000000000() page dumped because: kasan: bad access detected CPU: 3 PID: 391 Comm: systemd-udevd Tainted: G B L 4.5.0-next-20160316+ #12 [...] Call Trace: [<ffffffff8194889e>] dump_stack+0xdc/0x15e [<ffffffff819487c2>] ? _atomic_dec_and_lock+0xa2/0xa2 [<ffffffff814892b5>] ? __dump_page+0x185/0x330 [<ffffffff8150ffd6>] kasan_report_error+0x5e6/0x8b0 [<ffffffff814724cd>] ? kzfree+0x2d/0x40 [<ffffffff819c5bce>] ? mpi_free_limb_space+0xe/0x20 [<ffffffff819c469e>] ? mpi_powm+0x37e/0x16f0 [<ffffffff815109f1>] kasan_report+0x71/0xa0 [<ffffffff819c0353>] ? mpi_write_to_sgl+0x4e3/0x6f0 [<ffffffff8150ed34>] __asan_load8+0x64/0x70 [<ffffffff819c0353>] mpi_write_to_sgl+0x4e3/0x6f0 [<ffffffff819bfe70>] ? mpi_set_buffer+0x620/0x620 [<ffffffff819c0e6f>] ? mpi_cmp+0xbf/0x180 [<ffffffff8186e282>] rsa_verify+0x202/0x260 What's more, since lzeros can be anything from 1 to sizeof(mpi_limb_t)-1, the above will cause unaligned accesses which is bad on non-x86 archs. Fix the issue, by preparing the starting point p for the upcoming copy operation instead of shifting the source memory, i.e. alimb2. Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_write_sgl(): purge redundant pointer arithmeticNicolai Stange1-2/+1
Within the copying loop in mpi_write_sgl(), we have if (lzeros) { ... p -= lzeros; y = lzeros; } p = p - (sizeof(alimb) - y); If lzeros == 0, then y == 0, too. Thus, lzeros gets subtracted and added back again to p. Purge this redundancy. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_write_sgl(): fix style issue with lzero decrementNicolai Stange1-2/+2
Within the copying loop in mpi_write_sgl(), we have if (lzeros > 0) { ... lzeros -= sizeof(alimb); } However, at this point, lzeros < sizeof(alimb) holds. Make this fact explicit by rewriting the above to if (lzeros) { ... lzeros = 0; } Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05lib/mpi: mpi_write_sgl(): fix skipping of leading zero limbsNicolai Stange1-12/+9
Currently, if the number of leading zeros is greater than fits into a complete limb, mpi_write_sgl() skips them by iterating over them limb-wise. However, it fails to adjust its internal leading zeros tracking variable, lzeros, accordingly: it does a p -= sizeof(alimb); continue; which should really have been a lzeros -= sizeof(alimb); continue; Since lzeros never decreases if its initial value >= sizeof(alimb), nothing gets copied by mpi_write_sgl() in that case. Instead of skipping the high order zero limbs within the loop as shown above, fix the issue by adjusting the copying loop's bounds. Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-28lib/mpi: use "static inline" instead of "extern inline"Arnd Bergmann2-5/+5
When we use CONFIG_PROFILE_ALL_BRANCHES, every 'if()' introduces a static variable, but that is not allowed in 'extern inline' functions: mpi-inline.h:116:204: warning: '______f' is static but declared in inline function 'mpihelp_sub' which is not static mpi-inline.h:113:184: warning: '______f' is static but declared in inline function 'mpihelp_sub' which is not static mpi-inline.h:70:184: warning: '______f' is static but declared in inline function 'mpihelp_add' which is not static mpi-inline.h:56:204: warning: '______f' is static but declared in inline function 'mpihelp_add_1' which is not static This changes the MPI code to use 'static inline' instead, to get rid of hundreds of warnings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-28lib/mpi: avoid assembler warningArnd Bergmann1-1/+1
A wrapper around the umull assembly instruction might reuse the input register as an output, which is undefined on some ARM machines, as pointed out by this assembler warning: CC lib/mpi/generic_mpih-mul1.o /tmp/ccxJuxIy.s: Assembler messages: /tmp/ccxJuxIy.s:53: rdhi, rdlo and rm must all be different CC lib/mpi/generic_mpih-mul2.o /tmp/ccI0scAD.s: Assembler messages: /tmp/ccI0scAD.s:53: rdhi, rdlo and rm must all be different CC lib/mpi/generic_mpih-mul3.o /tmp/ccMvVQcp.s: Assembler messages: /tmp/ccMvVQcp.s:53: rdhi, rdlo and rm must all be different This changes the constraints to force different registers to be used as output. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-28lib/mpi: Endianness fixMichal Marek1-18/+21
The limbs are integers in the host endianness, so we can't simply iterate over the individual bytes. The current code happens to work on little-endian, because the order of the limbs in the MPI array is the same as the order of the bytes in each limb, but it breaks on big-endian. Fixes: 0f74fbf77d45 ("MPI: Fix mpi_read_buffer") Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-11-17lib/mpi: only require buffers as big as needed for the integerAndrzej Zaborowski1-4/+17
Since mpi_write_to_sgl and mpi_read_buffer explicitly left-align the integers being written it makes no sense to require a buffer big enough for the number + the leading zero bytes which are not written. The error returned also doesn't convey any information. So instead require only the size needed and return -EOVERFLOW to signal when buffer too short. Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-11-06Merge tag 'asm-generic-for-linus' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic cleanups from Arnd Bergmann: "The asm-generic changes for 4.4 are mostly a series from Christoph Hellwig to clean up various abuses of headers in there. The patch to rename the io-64-nonatomic-*.h headers caused some conflicts with new users, so I added a workaround that we can remove in the next merge window. The only other patch is a warning fix from Marek Vasut" * tag 'asm-generic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: asm-generic: temporarily add back asm-generic/io-64-nonatomic*.h asm-generic: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations gpio-mxc: stop including <asm-generic/bug> n_tracesink: stop including <asm-generic/bug> n_tracerouter: stop including <asm-generic/bug> mlx5: stop including <asm-generic/kmap_types.h> hifn_795x: stop including <asm-generic/kmap_types.h> drbd: stop including <asm-generic/kmap_types.h> move count_zeroes.h out of asm-generic move io-64-nonatomic*.h out of asm-generic
2015-10-20lib/mpi: fix off by one in mpi_read_raw_from_sglStephan Mueller1-1/+4
The patch fixes the analysis of the input data which contains an off by one. The issue is visible when the SGL contains one byte per SG entry. The code for checking for zero bytes does not operate on the data byte. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-10-15move count_zeroes.h out of asm-genericChristoph Hellwig2-2/+2
This header contains a few helpers currenly only used by the mpi implementation, and not default implementation of architecture code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2015-10-14lib/mpi: Add mpi sgl helpersTadeusz Struk1-0/+196
Add mpi_read_raw_from_sgl and mpi_write_to_sgl helpers. Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-08-25MPI: Fix mpi_read_bufferTadeusz Struk1-13/+25
Change mpi_read_buffer to return a number without leading zeros so that mpi_read_buffer and mpi_get_buffer return the same thing. Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds2-22/+71
Pull crypto update from Herbert Xu: "Here is the crypto update for 4.2: API: - Convert RNG interface to new style. - New AEAD interface with one SG list for AD and plain/cipher text. All external AEAD users have been converted. - New asymmetric key interface (akcipher). Algorithms: - Chacha20, Poly1305 and RFC7539 support. - New RSA implementation. - Jitter RNG. - DRBG is now seeded with both /dev/random and Jitter RNG. If kernel pool isn't ready then DRBG will be reseeded when it is. - DRBG is now the default crypto API RNG, replacing krng. - 842 compression (previously part of powerpc nx driver). Drivers: - Accelerated SHA-512 for arm64. - New Marvell CESA driver that supports DMA and more algorithms. - Updated powerpc nx 842 support. - Added support for SEC1 hardware to talitos" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (292 commits) crypto: marvell/cesa - remove COMPILE_TEST dependency crypto: algif_aead - Temporarily disable all AEAD algorithms crypto: af_alg - Forbid the use internal algorithms crypto: echainiv - Only hold RNG during initialisation crypto: seqiv - Add compatibility support without RNG crypto: eseqiv - Offer normal cipher functionality without RNG crypto: chainiv - Offer normal cipher functionality without RNG crypto: user - Add CRYPTO_MSG_DELRNG crypto: user - Move cryptouser.h to uapi crypto: rng - Do not free default RNG when it becomes unused crypto: skcipher - Allow givencrypt to be NULL crypto: sahara - propagate the error on clk_disable_unprepare() failure crypto: rsa - fix invalid select for AKCIPHER crypto: picoxcell - Update to the current clk API crypto: nx - Check for bogus firmware properties crypto: marvell/cesa - add DT bindings documentation crypto: marvell/cesa - add support for Kirkwood and Dove SoCs crypto: marvell/cesa - add support for Orion SoCs crypto: marvell/cesa - add allhwsupport module parameter crypto: marvell/cesa - add support for all armada SoCs ...
2015-06-16MPILIB: add mpi_read_buf() and mpi_get_size() helpersTadeusz Struk2-22/+71
Added a mpi_read_buf() helper function to export MPI to a buf provided by the user, and a mpi_get_size() helper, that tells the user how big the buf is. Changed mpi_free to use kzfree instead of kfree because it is used to free crypto keys. Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-13MPI: MIPS: Fix compilation error with GCC 5.1Jaedon Shin1-2/+2
This patch fixes mips compilation error: lib/mpi/generic_mpih-mul1.c: In function 'mpihelp_mul_1': lib/mpi/longlong.h:651:2: error: impossible constraint in 'asm' Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/10546/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-01-14MPILIB: Fix comparison of negative MPIsRasmus Villemoes1-1/+1
If u and v both represent negative integers and their limb counts happen to differ, mpi_cmp will always return a positive value - this is obviously bogus. u is smaller than v if and only if it is larger in absolute value. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
2015-01-14MPILIB: Fix obvious but harmless typoRasmus Villemoes1-1/+1
The macro MPN_COPY_INCR this occurs in isn't used anywhere. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: David Howells <dhowells@redhat.com>
2015-01-14MPILIB: Deobfuscate mpi_cmpRasmus Villemoes1-5/+3
The condition preceding 'return 1;' makes my head hurt. At this point, we know that u and v have the same sign; if they are negative, they compare opposite to how their absolute values compare (which mpihelp_cmp found for us), otherwise cmp itself is the answer. Negating cmp is ok since mpihelp_cmp returns {-1,0,1}; -INT_MIN==INT_MIN won't bite us. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
2013-09-25MPILIB: add module description and licenseKonstantin Khlebnikov1-0/+3
This patch fixes lack of license, otherwise mpi.ko taints kernel. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: David Howells <dhowells@redhat.com>
2013-07-19alpha: Modernize lib/mpi/longlong.hRichard Henderson1-10/+7
Remove the compile warning for __udiv_qrnnd not having a prototype. Use the __builtin_alpha_umulh introduced in gcc 4.0. Reviewed-and-Tested-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-06-12lib/mpi/mpicoder.c: looping issue, need stop when equal to zero, found by ↵Chen Gang1-1/+1
'EXTRA_FLAGS=-W'. For 'while' looping, need stop when 'nbytes == 0', or will cause issue. ('nbytes' is size_t which is always bigger or equal than zero). The related warning: (with EXTRA_CFLAGS=-W) lib/mpi/mpicoder.c:40:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-24MPILIB: disable usage of floating point registers on pariscHelge Deller1-2/+3
The umul_ppmm() macro for parisc uses the xmpyu assembler statement which does calculation via a floating point register. But usage of floating point registers inside the Linux kernel are not allowed and gcc will stop compilation due to the -mdisable-fpregs compiler option. Fix this by disabling the umul_ppmm() and udiv_qrnnd() macros. The mpilib will then use the generic built-in implementations instead. Signed-off-by: Helge Deller <deller@gmx.de>
2013-02-01mpilib: use DIV_ROUND_UP and remove unused macrosAndy Shevchenko2-8/+4
Remove MIN, MAX and ABS macros that are duplicates kernel's native implementation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-11-23MPI: Fix compilation on MIPS with GCC 4.4 and newerManuel Lauss1-2/+17
Since 4.4 GCC on MIPS no longer recognizes the "h" constraint, leading to this build failure: CC lib/mpi/generic_mpih-mul1.o lib/mpi/generic_mpih-mul1.c: In function 'mpihelp_mul_1': lib/mpi/generic_mpih-mul1.c:50:3: error: impossible constraint in 'asm' This patch updates MPI with the latest umul_ppm implementations for MIPS. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Cc: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Cc: James Morris <jmorris@namei.org> Patchwork: https://patchwork.linux-mips.org/patch/4612/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-10-08MPILIB: Provide a function to read raw data into an MPIDavid Howells1-0/+55
Provide a function to read raw data of a predetermined size into an MPI rather than expecting the size to be encoded within the data. The data is assumed to represent an unsigned integer, and the resulting MPI will be positive. The function looks like this: MPI mpi_read_raw_data(const void *, size_t); This is useful for reading ASN.1 integer primitives where the length is encoded in the ASN.1 metadata. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08MPILIB: Reinstate mpi_cmp[_ui]() and export for RSA signature verificationDavid Howells2-0/+71
Reinstate and export mpi_cmp() and mpi_cmp_ui() from the MPI library for use by RSA signature verification as per RFC3447 section 5.2.2 step 1. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08MPILIB: Provide count_leading/trailing_zeros() based on arch functionsDavid Howells3-139/+5
Provide count_leading/trailing_zeros() macros based on extant arch bit scanning functions rather than reimplementing from scratch in MPILIB. Whilst we're at it, turn count_foo_zeros(n, x) into n = count_foo_zeros(x). Also move the definition to asm-generic as other people may be interested in using it. Signed-off-by: David Howells <dhowells@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Cc: Arnd Bergmann <arnd@arndb.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-05-26Remove unused code from MPI libraryDmitry Kasatkin5-664/+0
MPI library is used by RSA verification implementation. Few files contains functions which are never called. James Morris has asked to remove all of them. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Requested-by: James Morris <james.l.morris@oracle.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
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