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author | Glenn Randers-Pehrson <glennrp at users.sourceforge.net> | 2015-11-19 09:12:43 -0600 |
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committer | Glenn Randers-Pehrson <glennrp at users.sourceforge.net> | 2015-11-19 09:12:43 -0600 |
commit | 68a6e6755bf88004ac3fa8f59c20e2cc7920cec2 (patch) | |
tree | 45cd90bbbc03334a1e7f15c3d78a2684df51a807 | |
parent | 8738633bd6c282ab0773f670a0cfa70953cedf72 (diff) | |
download | libpng-68a6e6755bf88004ac3fa8f59c20e2cc7920cec2.tar.gz |
[lbpng15] Rearrange terms in buffer length tests in pngrutil.c to
avoid potential overflow in calculations.
-rw-r--r-- | pngrutil.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/pngrutil.c b/pngrutil.c index f212bc8f2..429214e0f 100644 --- a/pngrutil.c +++ b/pngrutil.c @@ -1327,7 +1327,7 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* There should be at least one zero (the compression type byte) * following the separator, and we should be on it */ - if (slength < 1 || profile >= png_ptr->chunkdata + slength - 1) + if (slength < 1 || profile - png_ptr->chunkdata >= slength - 1) { png_free(png_ptr, png_ptr->chunkdata); png_ptr->chunkdata = NULL; @@ -1476,7 +1476,7 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) ++entry_start; /* A sample depth should follow the separator, and we should be on it */ - if (slength < 2 || entry_start > (png_bytep)png_ptr->chunkdata + slength - 2) + if (slength < 2 || entry_start - (png_bytep)png_ptr->chunkdata > slength - 2) { png_free(png_ptr, png_ptr->chunkdata); png_ptr->chunkdata = NULL; @@ -2005,7 +2005,7 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* We need to have at least 12 bytes after the purpose string * in order to get the parameter information. */ - if (length < 12 || endptr <= buf + 12) + if (endptr -buf <= 12) { png_warning(png_ptr, "Invalid pCAL data"); png_free(png_ptr, png_ptr->chunkdata); @@ -2417,7 +2417,7 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) /* Empty loop */ ; /* zTXt must have some text after the chunkdataword */ - if (slength < 2 || text >= png_ptr->chunkdata + slength - 2) + if (slength < 2 || text - png_ptr->chunkdata >= slength - 2) { png_warning(png_ptr, "Truncated zTXt chunk"); png_free(png_ptr, png_ptr->chunkdata); @@ -2554,7 +2554,7 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) * keyword */ - if (slength < 3 || lang >= png_ptr->chunkdata + slength - 3) + if (slength < 3 || png_ptr->chunkdata - lang >= slength - 3) { png_warning(png_ptr, "Truncated iTXt chunk"); png_free(png_ptr, png_ptr->chunkdata); |