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lib: fix memparse() to handle overflow

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Since '_parse_integer_limit()' (and so 'simple_strtoull()') is now capable
to handle overflow, adjust 'memparse()' to handle overflow (denoted by
ULLONG_MAX) returned from 'simple_strtoull()'.  Also use
'check_shl_overflow()' to catch an overflow possibly caused by processing
size suffix and denote it with ULLONG_MAX as well.

Link: https://lore.kernel.org/20260519172259.908980-3-dmantipov@yandex.ru
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Charlie Jenkins <thecharlesjenkins@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Dmitry Antipov 2026-05-19 20:22:53 +03:00 committed by Andrew Morton
parent 6e30111dbb
commit 9a4580db6e
1 changed files with 15 additions and 8 deletions
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23
lib/cmdline.c
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@ -150,39 +150,46 @@ EXPORT_SYMBOL(get_options);
unsigned long long memparse(const char *ptr, char **retptr)
{
char *endptr; /* local pointer to end of parsed string */
unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
unsigned int shl = 0;
/* Consume valid suffix even in case of overflow. */
switch (*endptr) {
case 'E':
case 'e':
ret <<= 10;
shl += 10;
fallthrough;
case 'P':
case 'p':
ret <<= 10;
shl += 10;
fallthrough;
case 'T':
case 't':
ret <<= 10;
shl += 10;
fallthrough;
case 'G':
case 'g':
ret <<= 10;
shl += 10;
fallthrough;
case 'M':
case 'm':
ret <<= 10;
shl += 10;
fallthrough;
case 'K':
case 'k':
ret <<= 10;
endptr++;
shl += 10;
fallthrough;
default:
break;
}
if (shl && likely(ptr != endptr)) {
/* Have valid suffix with preceding number. */
if (unlikely(check_shl_overflow(ret, shl, &ret)))
ret = ULLONG_MAX;
endptr++;
}
if (retptr)
*retptr = endptr;