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authorJ. Bruce Fields <bfields@citi.umich.edu>2008-01-22 17:40:42 -0500
committerJ. Bruce Fields <bfields@citi.umich.edu>2008-02-01 16:42:15 -0500
commit87d26ea7771ad637035e6bd5a2700d81ee9162da (patch)
treec1da6cd6fe03bfadb3276bd30423c7d4b105ef41 /fs
parent50431d94e732ba71b66a83c5435890728e313095 (diff)
downloadlinux-87d26ea7771ad637035e6bd5a2700d81ee9162da.tar.gz
nfsd: more careful input validation in nfsctl write methods
Neil Brown points out that we're checking buf[size-1] in a couple places
without first checking whether size is zero.

Actually, given the implementation of simple_transaction_get(), buf[-1]
is zero, so in both of these cases the subsequent check of the value of
buf[size-1] will catch this case.

But it seems fragile to depend on that, so add explicit checks for this
case.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/nfsctl.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index bc22e0b0343a..8516137cdbb0 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -304,6 +304,9 @@ static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
 	struct auth_domain *dom;
 	struct knfsd_fh fh;
 
+	if (size == 0)
+		return -EINVAL;
+
 	if (buf[size-1] != '\n')
 		return -EINVAL;
 	buf[size-1] = 0;
@@ -663,7 +666,7 @@ static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
 	char *recdir;
 	int len, status;
 
-	if (size > PATH_MAX || buf[size-1] != '\n')
+	if (size == 0 || size > PATH_MAX || buf[size-1] != '\n')
 		return -EINVAL;
 	buf[size-1] = 0;