[PATCH] initramfs: handle unrecognised decompressor when unpacking
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From: Phillip Lougher on 22 Apr 2010 23:10 The unpack routine fails to handle the decompress_method() returning unrecognised decompressor (compress_name == NULL). This results in the routine looping eventually oopsing on an out of bounds memory access. Note this bug is usually hidden, only triggering on trailing junk after one or more correct compressed blocks. The case of the compressed archive being complete junk is (by accident?) caught by the if (state != Reset) check because state is initialised to Start, but not updated due to the decompressor not having been called. Obviously if the junk is trailing a correctly decompressed buffer, state == Reset from the previous call to the decompressor. Reported-by: Aaro Koskinen <aaro.koskinen(a)iki.fi> Signed-off-by: Phillip Lougher <phillip(a)lougher.demon.co.uk> --- init/initramfs.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/init/initramfs.c b/init/initramfs.c index 37d3859..4b9c202 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -457,7 +457,8 @@ static char * __init unpack_to_rootfs(char *buf, unsigned len) compress_name); message = msg_buf; } - } + } else + error("junk in compressed archive"); if (state != Reset) error("junk in compressed archive"); this_header = saved_offset + my_inptr; -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |