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| author | Jann Horn <jannh@google.com> | 2020-10-15 20:12:43 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-16 11:11:21 -0700 |
| commit | df0c09c0117300cd03f6e8532527bf591d4eee65 (patch) | |
| tree | b77a1adcf9afeedfdf8932e79a7e03d796a2f879 /fs/coredump.c | |
| parent | 8f942eea12ae8c5a7cde85c145234b25e38de959 (diff) | |
| download | lwn-df0c09c0117300cd03f6e8532527bf591d4eee65.tar.gz lwn-df0c09c0117300cd03f6e8532527bf591d4eee65.zip | |
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: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Linus 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: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/coredump.c')
| -rw-r--r-- | fs/coredump.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index 76e7c10edfc0..5e24c06092c9 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -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) - return 0; - file->f_pos = pos; - cprm->written += n; - cprm->pos += n; - nr -= n; - } + + + if (dump_interrupted()) + return 0; + n = __kernel_write(file, addr, nr, &pos); + if (n != nr) + return 0; + file->f_pos = pos; + cprm->written += n; + cprm->pos += n; + return 1; } EXPORT_SYMBOL(dump_emit); |