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| author | Gleb Smirnoff <glebius@FreeBSD.org> | 2013-10-15 13:32:01 +0000 |
|---|---|---|
| committer | Gleb Smirnoff <glebius@FreeBSD.org> | 2013-10-15 13:32:01 +0000 |
| commit | a173916590ffbc512de8d0e99358e91e096f1877 (patch) | |
| tree | b53713980023a554633c3c1bf49769e9d964976a /lib/libc | |
| parent | aa93041d2c359f497749d46e83db645b1989d44a (diff) | |
| download | src-a173916590ffbc512de8d0e99358e91e096f1877.tar.gz src-a173916590ffbc512de8d0e99358e91e096f1877.zip | |
Make getutxent(3) more robust against bad utx.log files. Whenever we read
zeroes, don't stop processing the file, but read until its end or valid
data.
In collaboration with: ed
Notes
Notes:
svn path=/head/; revision=256537
Diffstat (limited to 'lib/libc')
| -rw-r--r-- | lib/libc/gen/getutxent.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/libc/gen/getutxent.c b/lib/libc/gen/getutxent.c index 20e8859f6cd7..1679aa43d097 100644 --- a/lib/libc/gen/getutxent.c +++ b/lib/libc/gen/getutxent.c @@ -122,9 +122,20 @@ getfutxent(struct futx *fu) if (udb == UTXDB_LOG) { uint16_t len; +retry: if (fread(&len, sizeof(len), 1, uf) != 1) return (-1); len = be16toh(len); + if (len == 0) { + /* + * XXX: Though zero-size records are valid in theory, + * they can never occur in practice. Zero-size records + * indicate file corruption. Seek one byte forward, to + * see if we can find a record there. + */ + ungetc('\0', uf); + goto retry; + } if (len > sizeof *fu) { /* Forward compatibility. */ if (fread(fu, sizeof(*fu), 1, uf) != 1) |