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Tim Sell
a5eb2188f5
Add necessary casting to several places where we were doing 32-bit
arithmetic (unsigned) to produce a 64-bit (unsigned long) result, to
prevent the theoretical possibility of a 32-bit overflow during the
arithmetic.
FYI, these are unsigned long:
ctx->param_bytes
ctx->allocbytes
These are unsigned int:
bytes
phdr->name_offset
phdr->name_length
Here is the test program demonstrating why we really need the casts:
void main()
{
unsigned int i;
unsigned long il;
printf("sizeof(int) =%dn",sizeof(i));
printf("sizeof(long)=%dn",sizeof(il));
i = (unsigned int)((((unsigned long)(1)) << 32) - 1);
printf("i = %un", i);
il = i+1;
printf("adding 1 withOUT cast = %lun", il);
il = (unsigned long)i+1;
printf("adding 1 WITH cast = %lun", il);
}
[selltc@mac tmp]$ gcc x.c -o x.out
[selltc@mac tmp]$ ./x.out
sizeof(int) =4
sizeof(long)=8
i = 4294967295
adding 1 withOUT cast = 0
adding 1 WITH cast = 4294967296
Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: David Binder <david.binder@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.