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| author | Chuck Lever <chuck.lever@oracle.com> | 2024-09-17 12:15:23 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-14 19:44:39 +0100 |
| commit | 90adbae9dd158da8331d9fdd32077bd1af04f553 (patch) | |
| tree | 8c914e305ae8152adfc7ccfea17a1a241805a3a0 /fs | |
| parent | af1db93c94819e6761f129b0189420462cd5ccf1 (diff) | |
| download | linux-90adbae9dd158da8331d9fdd32077bd1af04f553.tar.gz linux-90adbae9dd158da8331d9fdd32077bd1af04f553.tar.bz2 linux-90adbae9dd158da8331d9fdd32077bd1af04f553.zip | |
NFSD: Prevent a potential integer overflow
commit 7f33b92e5b18e904a481e6e208486da43e4dc841 upstream.
If the tag length is >= U32_MAX - 3 then the "length + 4" addition
can result in an integer overflow. Address this by splitting the
decoding into several steps so that decode_cb_compound4res() does
not have to perform arithmetic on the unsafe length value.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfsd/nfs4callback.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 51462f7958b3..55128de1a89d 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -285,17 +285,17 @@ static int decode_cb_compound4res(struct xdr_stream *xdr, u32 length; __be32 *p; - p = xdr_inline_decode(xdr, 4 + 4); + p = xdr_inline_decode(xdr, XDR_UNIT); if (unlikely(p == NULL)) goto out_overflow; - hdr->status = be32_to_cpup(p++); + hdr->status = be32_to_cpup(p); /* Ignore the tag */ - length = be32_to_cpup(p++); - p = xdr_inline_decode(xdr, length + 4); - if (unlikely(p == NULL)) + if (xdr_stream_decode_u32(xdr, &length) < 0) + goto out_overflow; + if (xdr_inline_decode(xdr, length) == NULL) + goto out_overflow; + if (xdr_stream_decode_u32(xdr, &hdr->nops) < 0) goto out_overflow; - p += XDR_QUADLEN(length); - hdr->nops = be32_to_cpup(p); return 0; out_overflow: return -EIO; |