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| author | Paul Eggert <eggert@cs.ucla.edu> | 2022-12-17 20:56:29 -0800 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2022-12-17 20:57:23 -0800 |
| commit | 8f600f2df293d539e9e9137f6f82faa1633b97c1 (patch) | |
| tree | b262d4dbfe65ec8e576845066bc254020c2025ec | |
| parent | b82f32d708e1329d06829e8d2d3734433acf9af3 (diff) | |
| download | sed-8f600f2df293d539e9e9137f6f82faa1633b97c1.tar.gz | |
sed: fix symlink bufsize readlink check
Problem reported by Hauke Mehrtens.
* sed/utils.c (follow_symlink): Fix typo when checking size of
second and later symlink, when that symlink is so large that it
does not fit into the buffer. Although the bug is not a buffer
overflow, it does cause sed to mishandle the symlink.
* testsuite/follow-symlinks.sh: Test for the bug.
| -rw-r--r-- | NEWS | 4 | ||||
| -rw-r--r-- | sed/utils.c | 2 | ||||
| -rw-r--r-- | testsuite/follow-symlinks.sh | 13 |
3 files changed, 18 insertions, 1 deletions
@@ -2,6 +2,10 @@ GNU sed NEWS -*- outline -*- * Noteworthy changes in release ?.? (????-??-??) [?] + 'sed --follow-symlinks -i' no longer mishandles an operand that is a + short symbolic link to a long symbolic link to a file. + [bug introduced in sed 4.9] + * Noteworthy changes in release 4.9 (2022-11-06) [stable] diff --git a/sed/utils.c b/sed/utils.c index 4bd6587..03243c2 100644 --- a/sed/utils.c +++ b/sed/utils.c @@ -345,7 +345,7 @@ follow_symlink (const char *fname) while ((linklen = (buf_used < buf_size ? readlink (fn, buf + buf_used, buf_size - buf_used) : 0)) - == buf_size) + == buf_size - buf_used) { buf = xpalloc (buf, &buf_size, 1, SSIZE_IDX_MAX, 1); if (num_links) diff --git a/testsuite/follow-symlinks.sh b/testsuite/follow-symlinks.sh index 880a80e..c418804 100644 --- a/testsuite/follow-symlinks.sh +++ b/testsuite/follow-symlinks.sh @@ -73,4 +73,17 @@ compare_ exp-la-abs out-la-abs || fail=1 ln -s la-loop la-loop || framework_failure_ sed --follow-symlinks -i s/a/b/ la-loop && fail=1 +# symlink of length 128 +long=d/ +for i in 2 3 4 5 6 7; do + long=$long$long +done +dir=${long%/d/} +file=$dir/xx +mkdir -p $dir && +echo x >$file && +ln -s $file yy && +ln -s yy xx || framework_failure_ +sed -i --follow-symlinks s/x/y/ xx || fail=1 + Exit $fail |