Commit df0c09c0 authored by Jann Horn's avatar Jann Horn Committed by Linus Torvalds
Browse files

coredump: let dump_emit() bail out on short writes 



dump_emit() has a retry loop, but there seems to be no way for that retry
logic to actually be used; and it was also buggy, writing the same data
repeatedly after a short write.

Let's just bail out on a short write.

Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarJann Horn <jannh@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/r/20200827114932.3572699-3-jannh@google.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8f942eea

fs/coredump.c

+11 −11
Original line number Diff line number Diff line
@@ -840,17 +840,17 @@ int dump_emit(struct coredump_params *cprm, const void *addr, int nr) 
	ssize_t n;

	if (cprm->written + nr > cprm->limit)

		return 0;

	while (nr) {





	if (dump_interrupted())

		return 0;

	n = __kernel_write(file, addr, nr, &pos);

		if (n <= 0)

	if (n != nr)

		return 0;

	file->f_pos = pos;

	cprm->written += n;

	cprm->pos += n;

		nr -= n;

	}



	return 1;

}

EXPORT_SYMBOL(dump_emit);