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| author | Waldemar Brodkorb <wbrodkorb@conet.de> | 2018-12-14 10:53:22 +0100 |
|---|---|---|
| committer | Waldemar Brodkorb <wbrodkorb@conet.de> | 2018-12-14 10:53:22 +0100 |
| commit | 365d19dfec4437b7a8227f594953a54c76863278 (patch) | |
| tree | c504d9ba1694c91b6838e825330d49f528c2f6cf /libc/inet/ethers.c | |
| parent | 51e75b39838427f5eb66b0038672b2ca8ced8e93 (diff) | |
fix issues in ethers.c
Old version manages strings the regular way (i.e. counting on zero-ended
sequences). In fact strings captured from the /etc/ethers file are
'\n'-ended. So, for example, using strchr function could lead to buffer
overflow.
Reported-by: "Andrey V. Zhmurin" <zhmurin_a@mcst.ru
Diffstat (limited to 'libc/inet/ethers.c')
| -rw-r--r-- | libc/inet/ethers.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/libc/inet/ethers.c b/libc/inet/ethers.c index 857e5d165..caa4a644c 100644 --- a/libc/inet/ethers.c +++ b/libc/inet/ethers.c @@ -32,11 +32,11 @@ static const char *__ether_line(const char *line, struct ether_addr *addr) if (!res) return NULL; - while (*line && (*line != ' ') && (*line != '\t')) + while (*line && (*line != '\n') && (*line != ' ') && (*line != '\t')) line++; - while (*line && ((*line == ' ') || (*line == '\t'))) + while (*line && (*line != '\n') && ((*line == ' ') || (*line == '\t'))) line++; - return (*line) ? line : NULL; + return (*line && (*line != '\n')) ? line : NULL; } /* @@ -45,9 +45,7 @@ static const char *__ether_line(const char *line, struct ether_addr *addr) */ static const char *__ether_line_w(char *line, struct ether_addr *addr) { - char *end = strchr(line, '#'); - if (!end) - end = strchr(line, '\n'); + char *end = strpbrk(line, "#\n"); if (end) *end = '\0'; return __ether_line(line, addr); |