Comments
Patch
@@ -824,20 +824,20 @@ int se_dev_check_shutdown(struct se_device *dev)
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);
+
+ if (max_sectors != aligned_max_sectors)
+ pr_info("Rounding down aligned max_sectors from %u to %u\n",
+ max_sectors, aligned_max_sectors);
- return max_sectors;
+ return aligned_max_sectors;
}
void se_dev_set_default_attribs(
This is a note to let you know that I have just added a patch titled target: Avoid integer overflow in se_dev_align_max_sectors() to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From 1f66d2d5d4094baeafa28a1b729ab7c5a1e63030 Mon Sep 17 00:00:00 2001 From: Roland Dreier <roland@purestorage.com> Date: Wed, 31 Oct 2012 09:16:45 -0700 Subject: [PATCH] target: Avoid integer overflow in se_dev_align_max_sectors() X-Extended-Stable: 3.5 commit 3e03989b5868acf69a391a424dc71fcd6cc48167 upstream. 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> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> [ herton: unfuzz patch ] Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- drivers/target/target_core_device.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) -- 1.7.9.5