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) Reported-by: Aaro Koskinen <[email protected]> Signed-off-by: Andy Shevchenko <[email protected]> --- Waiting for Aaro's Tested-by: tag, that's why RFT. Meanwhile I will update test-hexdump to cover all corner case in overflow. Linus, it would be nice to promote the fix when we get Aaro's confirmation. lib/hexdump.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/hexdump.c b/lib/hexdump.c index 8d74c20..992457b 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -169,11 +169,15 @@ int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize, } } 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) -- 2.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
