Rich reported this bug privately. Here's a proposed patch. I could have fixed the underlying problem with explicit casts to a wider type (including floating point types), but this seemed cleanest, if perhaps a little too subtle. I'd rather not write a comment in each of three places, and didn't really want to factor out a 3-input function just to compute each next_pad value.
Along the way, I noticed that an unreasonably large width caused trouble, but I'm not inclined to worry about it: $ : | od -An -a -w$(echo 2^32-1|bc) od: memory exhausted >From 19a4227793820f74bd6ca503ded3fafe65425eff Mon Sep 17 00:00:00 2001 From: Jim Meyering <[email protected]> Date: Sat, 1 Jun 2013 19:20:06 -0700 Subject: [PATCH] od: -wN, N>64K, avoid misbehavior on systems with 32-bit size_t * src/od.c (PRINT_FIELDS): Declare "i" to be of type uintmax_t, so that the numerator in the expression for "next_pad" does not overflow. (print_named_ascii): Likewise. (print_ascii): Likewise. Bug introduced via commit v6.12-42-g20c0b87. * tests/misc/od.pl: Exercise each of the three affected code paths. * NEWS (Bug fixes): Mention it. Reported by Rich Burridge. --- NEWS | 4 ++++ THANKS.in | 1 + src/od.c | 6 +++--- tests/misc/od.pl | 7 +++++++ 4 files changed, 15 insertions(+), 3 deletions(-) diff --git a/NEWS b/NEWS index 721e05b..cad5eee 100644 --- a/NEWS +++ b/NEWS @@ -16,10 +16,14 @@ GNU coreutils NEWS -*- outline -*- mkdir, mkfifo, and mknod now work better when creating a file in a directory with a default ACL whose umask disagrees with the process's umask, on a system such as GNU/Linux where directory ACL umasks override process umasks. [bug introduced in coreutils-6.0] + od -wN with N larger than 64K on a system with 32-bit size_t would + print approximately 2*N bytes of extraneous padding. + [Bug introduced in coreutils-7.0] + tail --retry -f now waits for the files specified to appear. Before, tail would immediately exit when such a file is inaccessible during the initial open. [This bug was introduced when inotify support was added in coreutils-7.5] diff --git a/THANKS.in b/THANKS.in index 67b60b9..f399d77 100644 --- a/THANKS.in +++ b/THANKS.in @@ -519,10 +519,11 @@ Rainer Orth [email protected] Ralf W. Stephan [email protected] Ralph Loader [email protected] Rasmus Borup Hansen [email protected] Raul Miller [email protected] Raúl Núñez de Arenas Coronado [email protected] +Rich Burridge [email protected] Richard A Downing [email protected] Richard Braakman [email protected] Richard Dawe [email protected] Richard J. Rauenzahn [email protected] Richard Neill [email protected] diff --git a/src/od.c b/src/od.c index e8cab46..1c23401 100644 --- a/src/od.c +++ b/src/od.c @@ -398,11 +398,11 @@ and so on for G, T, P, E, Z, Y.\n\ static void \ N (size_t fields, size_t blank, void const *block, \ char const *FMT_STRING, int width, int pad) \ { \ T const *p = block; \ - size_t i; \ + uintmax_t i; \ int pad_remaining = pad; \ for (i = fields; blank < i; i--) \ { \ int next_pad = pad * (i - 1) / fields; \ int adjusted_width = pad_remaining - next_pad + width; \ @@ -454,11 +454,11 @@ static void print_named_ascii (size_t fields, size_t blank, void const *block, const char *unused_fmt_string _GL_UNUSED, int width, int pad) { unsigned char const *p = block; - size_t i; + uintmax_t i; int pad_remaining = pad; for (i = fields; blank < i; i--) { int next_pad = pad * (i - 1) / fields; int masked_c = *p++ & 0x7f; @@ -485,11 +485,11 @@ static void print_ascii (size_t fields, size_t blank, void const *block, const char *unused_fmt_string _GL_UNUSED, int width, int pad) { unsigned char const *p = block; - size_t i; + uintmax_t i; int pad_remaining = pad; for (i = fields; blank < i; i--) { int next_pad = pad * (i - 1) / fields; unsigned char c = *p++; diff --git a/tests/misc/od.pl b/tests/misc/od.pl index 0649b1c..fb579aa 100755 --- a/tests/misc/od.pl +++ b/tests/misc/od.pl @@ -55,10 +55,17 @@ my @Tests = # Ensure that od -j doesn't fseek across a nonempty file in /proc, # even if the kernel reports that the file has stat.st_size = 0. ['j-proc', "-An -c -j $proc_file_byte_count $proc_file", {IN=>{f2=>'e'}}, {OUT=>" e\n"}], + + # Ensure that a large width does not cause trouble. + # From coreutils-7.0 through coreutils-8.21, these would print + # approximately 128KiB of padding. + ['wide-a', '-a -w65537 -An', {IN=>{g=>'x'}}, {OUT=>" x\n"}], + ['wide-c', '-c -w65537 -An', {IN=>{g=>'x'}}, {OUT=>" x\n"}], + ['wide-x', '-tx1 -w65537 -An', {IN=>{g=>'B'}}, {OUT=>" 42\n"}], ); my $save_temps = $ENV{DEBUG}; my $verbose = $ENV{VERBOSE}; -- 1.8.3.101.g727a46b
