On Tue, 17 Oct 2017 00:39:14 +0200 Andrea Arcangeli <aarcange@xxxxxxxxxx> wrote: > kernel BUG at fs/hugetlbfs/inode.c:484! > RIP: 0010:[<ffffffff815f8520>] [<ffffffff815f8520>] remove_inode_hugepages+0x3d0/0x410 > Call Trace: > [<ffffffff815f95b9>] hugetlbfs_setattr+0xd9/0x130 > [<ffffffff81526312>] notify_change+0x292/0x410 > [<ffffffff816cc6b6>] ? security_inode_need_killpriv+0x16/0x20 > [<ffffffff81503c65>] do_truncate+0x65/0xa0 > [<ffffffff81504035>] ? do_sys_ftruncate.constprop.3+0xe5/0x180 > [<ffffffff8150406a>] do_sys_ftruncate.constprop.3+0x11a/0x180 > [<ffffffff8150410e>] SyS_ftruncate+0xe/0x10 > [<ffffffff81999f27>] tracesys+0xd9/0xde > > This oops was caused by the lack of i_size check in > hugetlb_mcopy_atomic_pte. mmap() can still succeed beyond the end of > the i_size after vmtruncate zapped vmas in those ranges, but the > faults must not succeed, and that includes UFFDIO_COPY. > > We could differentiate the retval to userland to represent a SIGBUS > like a page fault would do (vs SIGSEGV), but it doesn't seem very > useful and we'd need to pick a random retval as there's no meaningful > syscall retval that would differentiate from SIGSEGV and SIGBUS, > there's just -EFAULT. > > Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> No cc:stable? The patch applies to 4.13 textually... -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
