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| author | Phillip Lougher <phillip@lougher.demon.co.uk> | 2009-09-23 15:57:37 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-24 07:21:05 -0700 |
| commit | 6a8811629e9aa611aa710162f9e02020bba52c87 (patch) | |
| tree | d3b8ff16950f5cda94b3259fbfa097aea9cb1e5f /lib | |
| parent | 3354f73b24c6d392ed7fd5583cfcc7604c1934ae (diff) | |
| download | lwn-6a8811629e9aa611aa710162f9e02020bba52c87.tar.gz lwn-6a8811629e9aa611aa710162f9e02020bba52c87.zip | |
lzma/gzip: fix potential oops when input data is truncated
If the lzma/gzip decompressors are called with insufficient input data
(len > 0 & fill = NULL), they will attempt to call the fill function to
obtain more data, leading to a kernel oops.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/decompress_inflate.c | 8 | ||||
| -rw-r--r-- | lib/decompress_unlzma.c | 10 |
2 files changed, 17 insertions, 1 deletions
diff --git a/lib/decompress_inflate.c b/lib/decompress_inflate.c index 68dfce59c1b8..fc686c7a0a0d 100644 --- a/lib/decompress_inflate.c +++ b/lib/decompress_inflate.c @@ -27,6 +27,11 @@ #define GZIP_IOBUF_SIZE (16*1024) +static int nofill(void *buffer, unsigned int len) +{ + return -1; +} + /* Included from initramfs et al code */ STATIC int INIT gunzip(unsigned char *buf, int len, int(*fill)(void*, unsigned int), @@ -76,6 +81,9 @@ STATIC int INIT gunzip(unsigned char *buf, int len, goto gunzip_nomem4; } + if (!fill) + fill = nofill; + if (len == 0) len = fill(zbuf, GZIP_IOBUF_SIZE); diff --git a/lib/decompress_unlzma.c b/lib/decompress_unlzma.c index 0b954e04bd30..ca82fde81c8f 100644 --- a/lib/decompress_unlzma.c +++ b/lib/decompress_unlzma.c @@ -82,6 +82,11 @@ struct rc { #define RC_MODEL_TOTAL_BITS 11 +static int nofill(void *buffer, unsigned int len) +{ + return -1; +} + /* Called twice: once at startup and once in rc_normalize() */ static void INIT rc_read(struct rc *rc) { @@ -97,7 +102,10 @@ static inline void INIT rc_init(struct rc *rc, int (*fill)(void*, unsigned int), char *buffer, int buffer_size) { - rc->fill = fill; + if (fill) + rc->fill = fill; + else + rc->fill = nofill; rc->buffer = (uint8_t *)buffer; rc->buffer_size = buffer_size; rc->buffer_end = rc->buffer + rc->buffer_size; |