Mercurial > hg > nginx
view src/core/ngx_parse.c @ 7094:c7d4017c8876
Secure link: fixed stack buffer overflow.
When secure link checksum has length of 23 or 24 bytes, decoded base64 value
could occupy 17 or 18 bytes which is more than 16 bytes previously allocated
for it on stack. The buffer overflow does not have any security implications
since only one local variable was corrupted and this variable was not used in
this case.
The fix is to increase buffer size up to 18 bytes. Useless buffer size
initialization is removed as well.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 22 Aug 2017 21:22:59 +0300 |
parents | 87cf6ddb41c2 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> ssize_t ngx_parse_size(ngx_str_t *line) { u_char unit; size_t len; ssize_t size, scale, max; len = line->len; if (len == 0) { return NGX_ERROR; } unit = line->data[len - 1]; switch (unit) { case 'K': case 'k': len--; max = NGX_MAX_SIZE_T_VALUE / 1024; scale = 1024; break; case 'M': case 'm': len--; max = NGX_MAX_SIZE_T_VALUE / (1024 * 1024); scale = 1024 * 1024; break; default: max = NGX_MAX_SIZE_T_VALUE; scale = 1; } size = ngx_atosz(line->data, len); if (size == NGX_ERROR || size > max) { return NGX_ERROR; } size *= scale; return size; } off_t ngx_parse_offset(ngx_str_t *line) { u_char unit; off_t offset, scale, max; size_t len; len = line->len; if (len == 0) { return NGX_ERROR; } unit = line->data[len - 1]; switch (unit) { case 'K': case 'k': len--; max = NGX_MAX_OFF_T_VALUE / 1024; scale = 1024; break; case 'M': case 'm': len--; max = NGX_MAX_OFF_T_VALUE / (1024 * 1024); scale = 1024 * 1024; break; case 'G': case 'g': len--; max = NGX_MAX_OFF_T_VALUE / (1024 * 1024 * 1024); scale = 1024 * 1024 * 1024; break; default: max = NGX_MAX_OFF_T_VALUE; scale = 1; } offset = ngx_atoof(line->data, len); if (offset == NGX_ERROR || offset > max) { return NGX_ERROR; } offset *= scale; return offset; } ngx_int_t ngx_parse_time(ngx_str_t *line, ngx_uint_t is_sec) { u_char *p, *last; ngx_int_t value, total, scale; ngx_int_t max, cutoff, cutlim; ngx_uint_t valid; enum { st_start = 0, st_year, st_month, st_week, st_day, st_hour, st_min, st_sec, st_msec, st_last } step; valid = 0; value = 0; total = 0; cutoff = NGX_MAX_INT_T_VALUE / 10; cutlim = NGX_MAX_INT_T_VALUE % 10; step = is_sec ? st_start : st_month; p = line->data; last = p + line->len; while (p < last) { if (*p >= '0' && *p <= '9') { if (value >= cutoff && (value > cutoff || *p - '0' > cutlim)) { return NGX_ERROR; } value = value * 10 + (*p++ - '0'); valid = 1; continue; } switch (*p++) { case 'y': if (step > st_start) { return NGX_ERROR; } step = st_year; max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24 * 365); scale = 60 * 60 * 24 * 365; break; case 'M': if (step >= st_month) { return NGX_ERROR; } step = st_month; max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24 * 30); scale = 60 * 60 * 24 * 30; break; case 'w': if (step >= st_week) { return NGX_ERROR; } step = st_week; max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24 * 7); scale = 60 * 60 * 24 * 7; break; case 'd': if (step >= st_day) { return NGX_ERROR; } step = st_day; max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24); scale = 60 * 60 * 24; break; case 'h': if (step >= st_hour) { return NGX_ERROR; } step = st_hour; max = NGX_MAX_INT_T_VALUE / (60 * 60); scale = 60 * 60; break; case 'm': if (p < last && *p == 's') { if (is_sec || step >= st_msec) { return NGX_ERROR; } p++; step = st_msec; max = NGX_MAX_INT_T_VALUE; scale = 1; break; } if (step >= st_min) { return NGX_ERROR; } step = st_min; max = NGX_MAX_INT_T_VALUE / 60; scale = 60; break; case 's': if (step >= st_sec) { return NGX_ERROR; } step = st_sec; max = NGX_MAX_INT_T_VALUE; scale = 1; break; case ' ': if (step >= st_sec) { return NGX_ERROR; } step = st_last; max = NGX_MAX_INT_T_VALUE; scale = 1; break; default: return NGX_ERROR; } if (step != st_msec && !is_sec) { scale *= 1000; max /= 1000; } if (value > max) { return NGX_ERROR; } value *= scale; if (total > NGX_MAX_INT_T_VALUE - value) { return NGX_ERROR; } total += value; value = 0; while (p < last && *p == ' ') { p++; } } if (!valid) { return NGX_ERROR; } if (!is_sec) { if (value > NGX_MAX_INT_T_VALUE / 1000) { return NGX_ERROR; } value *= 1000; } if (total > NGX_MAX_INT_T_VALUE - value) { return NGX_ERROR; } return total + value; }