From: Andy Shevchenko <[email protected]> Subject: lib/hexdump.c: truncate output in case of overflow
There is a classical off-by-one error in case when we try to place, for example, 1+1 bytes as hex in the buffer of size 6. The expected result is to get an output truncated, but in the reality we get 6 bytes filed followed by terminating NUL. Change the logic how we fill the output in case of byte dumping into limited space. This will follow the snprintf() behaviour by truncating output even on half bytes. Fixes: 114fc1afb2de (hexdump: make it return number of bytes placed in buffer) Signed-off-by: Andy Shevchenko <[email protected]> Reported-by: Aaro Koskinen <[email protected]> Tested-by: Aaro Koskinen <[email protected]> Cc: Al Viro <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> --- lib/hexdump.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff -puN lib/hexdump.c~hexdump-truncate-output-in-case-of-overflow lib/hexdump.c --- a/lib/hexdump.c~hexdump-truncate-output-in-case-of-overflow +++ a/lib/hexdump.c @@ -169,11 +169,15 @@ int hex_dump_to_buffer(const void *buf, } } else { for (j = 0; j < len; j++) { - if (linebuflen < lx + 3) + if (linebuflen < lx + 2) goto overflow2; ch = ptr[j]; linebuf[lx++] = hex_asc_hi(ch); + if (linebuflen < lx + 2) + goto overflow2; linebuf[lx++] = hex_asc_lo(ch); + if (linebuflen < lx + 2) + goto overflow2; linebuf[lx++] = ' '; } if (j) _ -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
