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Merge tag 'block-6.6-2023-10-27' of git://git.kernel.dk/linux

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Pull block fix from Jens Axboe:
 "Just a single fix for a potential divide-by-zero, introduced in this
  cycle"

* tag 'block-6.6-2023-10-27' of git://git.kernel.dk/linux:
  blk-throttle: check for overflow in calculate_bytes_allowed
This commit is contained in:
Linus Torvalds
2023-10-27 14:01:59 -10:00
parent 832328c9f8 2dd710d476
commit 2dc4e0f455
1 changed files with 6 additions and 0 deletions
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6
block/blk-throttle.c
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@@ -723,6 +723,12 @@ static unsigned int calculate_io_allowed(u32 iops_limit,
static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed)
{
/*
* Can result be wider than 64 bits?
* We check against 62, not 64, due to ilog2 truncation.
*/
if (ilog2(bps_limit) + ilog2(jiffy_elapsed) - ilog2(HZ) > 62)
return U64_MAX;
return mul_u64_u64_div_u64(bps_limit, (u64)jiffy_elapsed, (u64)HZ);
}