• Hannes Reinecke's avatar
    bio: return EINTR if copying to user space got interrupted · 2d99b55d
    Hannes Reinecke authored
    Commit 35dc2483 introduced a check for
    current->mm to see if we have a user space context and only copies data
    if we do. Now if an IO gets interrupted by a signal data isn't copied
    into user space any more (as we don't have a user space context) but
    user space isn't notified about it.
    This patch modifies the behaviour to return -EINTR from bio_uncopy_user()
    to notify userland that a signal has interrupted the syscall, otherwise
    it could lead to a situation where the caller may get a buffer with
    no data returned.
    This can be reproduced by issuing SG_IO ioctl()s in one thread while
    constantly sending signals to it.
    Fixes: 35dc2483 [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal
    Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
    Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
    Cc: stable@vger.kernel.org # v.3.11+
    Signed-off-by: default avatarJens Axboe <axboe@fb.com>
bio.c 48.6 KB