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| author | Chuck Lever <chuck.lever@oracle.com> | 2021-11-14 15:16:04 -0500 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2021-11-15 15:33:10 -0500 |
| commit | c0019b7db1d7ac62c711cda6b357a659d46428fe (patch) | |
| tree | 89686f8c5bb9f59109ca919a3539c89c31d06b22 | |
| parent | 80479eb862102f9513e93fcf726c78cc0be2e3b2 (diff) | |
| download | linux-c0019b7db1d7ac62c711cda6b357a659d46428fe.tar.gz | |
NFSD: Fix exposure in nfsd4_decode_bitmap()
rtm@csail.mit.edu reports:
> nfsd4_decode_bitmap4() will write beyond bmval[bmlen-1] if the RPC
> directs it to do so. This can cause nfsd4_decode_state_protect4_a()
> to write client-supplied data beyond the end of
> nfsd4_exchange_id.spo_must_allow[] when called by
> nfsd4_decode_exchange_id().
Rewrite the loops so nfsd4_decode_bitmap() cannot iterate beyond
@bmlen.
Reported by: rtm@csail.mit.edu
Fixes: d1c263a031e8 ("NFSD: Replace READ* macros in nfsd4_decode_fattr()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 9b609aac47e10..5bdfaa43c99df 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -288,11 +288,8 @@ nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen) p = xdr_inline_decode(argp->xdr, count << 2); if (!p) return nfserr_bad_xdr; - i = 0; - while (i < count) - bmval[i++] = be32_to_cpup(p++); - while (i < bmlen) - bmval[i++] = 0; + for (i = 0; i < bmlen; i++) + bmval[i] = (i < count) ? be32_to_cpup(p++) : 0; return nfs_ok; } |