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target: Avoid integer overflow in se_dev_align_max_sectors()

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The expression (max_sectors * block_size) might overflow a u32
(indeed, since iblock sets max_hw_sectors to UINT_MAX, it is
guaranteed to overflow and end up with a much-too-small result in many
common cases).  Fix this by doing an equivalent calculation that
doesn't require multiplication.

While we're touching this code, avoid splitting a printk format across
two lines and use pr_info(...) instead of printk(KERN_INFO ...).

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Roland Dreier 2012-10-31 09:16:45 -07:00 committed by Nicholas Bellinger
parent 0d0f9dfb31
commit 3e03989b58
1 changed files with 9 additions and 9 deletions
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18
drivers/target/target_core_device.c
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@ -850,20 +850,20 @@ int se_dev_check_shutdown(struct se_device *dev)
static u32 se_dev_align_max_sectors(u32 max_sectors, u32 block_size)
{
u32 tmp, aligned_max_sectors;
u32 aligned_max_sectors;
u32 alignment;
/*
* Limit max_sectors to a PAGE_SIZE aligned value for modern
* transport_allocate_data_tasks() operation.
*/
tmp = rounddown((max_sectors * block_size), PAGE_SIZE);
aligned_max_sectors = (tmp / block_size);
if (max_sectors != aligned_max_sectors) {
printk(KERN_INFO "Rounding down aligned max_sectors from %u"
" to %u\n", max_sectors, aligned_max_sectors);
return aligned_max_sectors;
}
alignment = max(1ul, PAGE_SIZE / block_size);
aligned_max_sectors = rounddown(max_sectors, alignment);
return max_sectors;
if (max_sectors != aligned_max_sectors)
pr_info("Rounding down aligned max_sectors from %u to %u\n",
max_sectors, aligned_max_sectors);
return aligned_max_sectors;
}
void se_dev_set_default_attribs(