linux-toradex.git/lib/mpi/mpicoder.c, branch v6.4-rc1

lib/mpi: Fix buffer overrun when SG is too long

2023-01-06T09:15:46+00:00

The helper mpi_read_raw_from_sgl sets the number of entries in
the SG list according to nbytes.  However, if the last entry
in the SG list contains more data than nbytes, then it may overrun
the buffer because it only allocates enough memory for nbytes.

Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers")
Reported-by: Roberto Sassu 
Signed-off-by: Herbert Xu 
Reviewed-by: Eric Biggers 
Signed-off-by: Herbert Xu

lib/mpi: fix spelling mistakes

2021-07-01T18:06:05+00:00

Fix some spelling mistakes in comments:
flaged ==> flagged
bufer ==> buffer
multipler ==> multiplier
MULTIPLER ==> MULTIPLIER
leaset ==> least
chnage ==> change

Link: https://lkml.kernel.org/r/20210604074401.12198-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei 
Cc: Herbert Xu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/mpi: Extend the MPI library

2020-09-25T07:48:53+00:00

Expand the mpi library based on libgcrypt, and the ECC algorithm of
mpi based on libgcrypt requires these functions.
Some other algorithms will be developed based on mpi ecc, such as SM2.

Signed-off-by: Tianjia Zhang 
Tested-by: Xufeng Zhang 
Signed-off-by: Herbert Xu

lib/mpi: kunmap after finishing accessing buffer

2017-08-22T06:45:01+00:00

Using sg_miter_start and sg_miter_next, the buffer of an SG is kmap'ed
to *buff. The current code calls sg_miter_stop (and thus kunmap) on the
SG entry before the last access of *buff.

The patch moves the sg_miter_stop call after the last access to *buff to
ensure that the memory pointed to by *buff is still mapped.

Fixes: 4816c9406430 ("lib/mpi: Fix SG miter leak")
Cc: 
Signed-off-by: Stephan Mueller 
Signed-off-by: Herbert Xu

lib/mpi: Fix SG miter leak

2016-07-29T10:30:16+00:00

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 
Tested-by: Nicolai Stange 
Signed-off-by: Herbert Xu

lib/mpi: Do not do sg_virt

2016-07-01T15:45:18+00:00

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

crypto: rsa - Generate fixed-length output

2016-07-01T15:45:18+00:00

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

lib/mpi: refactor mpi_read_from_buffer() in terms of mpi_read_raw_data()

2016-05-31T08:42:01+00:00

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 
Signed-off-by: Herbert Xu

lib/mpi: mpi_read_from_buffer(): sanitize short buffer printk

2016-05-31T08:42:00+00:00

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 
Signed-off-by: Herbert Xu

lib/mpi: mpi_read_from_buffer(): return -EINVAL upon too short buffer

2016-05-31T08:42:00+00:00

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 
Signed-off-by: Herbert Xu