The patch titled Subject: mm: selftests: fix potential integer overflow on shift of a int has been added to the -mm tree. Its filename is mm-selftests-for-exclusive-device-memory-fix.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-selftests-for-exclusive-device-memory-fix.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-selftests-for-exclusive-device-memory-fix.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Colin Ian King <colin.king@xxxxxxxxxxxxx> Subject: mm: selftests: fix potential integer overflow on shift of a int The left shift of the int mapped is evaluated using 32 bit arithmetic and then assigned to an unsigned long. In the case where mapped is 0x80000 when PAGE_SHIFT is 12 will lead to the upper bits being sign extended in the unsigned long. Larger values can lead to an int overflow. Avoid this by making mapped an unsigned long. Addresses-Coverity: ("Uninitentional integer overflow") Link: https://lkml.kernel.org/r/20210526170530.3766167-1-colin.king@xxxxxxxxxxxxx Fixes: 8b2a105c3794 ("mm: selftests for exclusive device memory") Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> Cc: Alistair Popple <apopple@xxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxx> Cc: Ralph Campbell <rcampbell@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/test_hmm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/lib/test_hmm.c~mm-selftests-for-exclusive-device-memory-fix +++ a/lib/test_hmm.c @@ -733,7 +733,8 @@ static int dmirror_exclusive(struct dmir mmap_read_lock(mm); for (addr = start; addr < end; addr = next) { - int i, mapped; + unsigned long mapped; + int i; if (end < addr + (ARRAY_SIZE(pages) << PAGE_SHIFT)) next = end; _ Patches currently in -mm which might be from colin.king@xxxxxxxxxxxxx are scripts-spellingtxt-add-more-spellings-to-spellingtxt.patch ocfs2-remove-redundant-assignment-to-pointer-queue.patch mm-selftests-for-exclusive-device-memory-fix.patch