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authorMiklos Szeredi <mszeredi@redhat.com>2019-11-12 11:49:04 +0100
committerMiklos Szeredi <mszeredi@redhat.com>2019-11-12 11:49:04 +0100
commiteb59bd17d2fa6e5e84fba61a5ebdea984222e6d5 (patch)
treea644b87e95b4245db9a2a716f56e54fe8b82179c /fs/fuse
parent31f4f5b495a62c9a8b15b1c3581acd5efeb9af8c (diff)
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fuse: verify attributes
If a filesystem returns negative inode sizes, future reads on the file were causing the cpu to spin on truncate_pagecache. Create a helper to validate the attributes. This now does two things: - check the file mode - check if the file size fits in i_size without overflowing Reported-by: Arijit Banerjee <arijit@rubrik.com> Fixes: d8a5ba45457e ("[PATCH] FUSE - core") Cc: <stable@vger.kernel.org> # v2.6.14 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse')
-rw-r--r--fs/fuse/dir.c22
-rw-r--r--fs/fuse/fuse_i.h2
-rw-r--r--fs/fuse/readdir.c2
3 files changed, 19 insertions, 7 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 54d638f9ba1c..ca4ddbe21ec0 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -248,7 +248,8 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
kfree(forget);
if (ret == -ENOMEM)
goto out;
- if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
+ if (ret || fuse_invalid_attr(&outarg.attr) ||
+ (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
goto invalid;
forget_all_cached_acls(inode);
@@ -319,6 +320,12 @@ int fuse_valid_type(int m)
S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
}
+bool fuse_invalid_attr(struct fuse_attr *attr)
+{
+ return !fuse_valid_type(attr->mode) ||
+ attr->size > LLONG_MAX;
+}
+
int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
struct fuse_entry_out *outarg, struct inode **inode)
{
@@ -350,7 +357,7 @@ int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name
err = -EIO;
if (!outarg->nodeid)
goto out_put_forget;
- if (!fuse_valid_type(outarg->attr.mode))
+ if (fuse_invalid_attr(&outarg->attr))
goto out_put_forget;
*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
@@ -475,7 +482,8 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
goto out_free_ff;
err = -EIO;
- if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
+ if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid) ||
+ fuse_invalid_attr(&outentry.attr))
goto out_free_ff;
ff->fh = outopen.fh;
@@ -583,7 +591,7 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args,
goto out_put_forget_req;
err = -EIO;
- if (invalid_nodeid(outarg.nodeid))
+ if (invalid_nodeid(outarg.nodeid) || fuse_invalid_attr(&outarg.attr))
goto out_put_forget_req;
if ((outarg.attr.mode ^ mode) & S_IFMT)
@@ -942,7 +950,8 @@ static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
args.out_args[0].value = &outarg;
err = fuse_simple_request(fc, &args);
if (!err) {
- if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
+ if (fuse_invalid_attr(&outarg.attr) ||
+ (inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
make_bad_inode(inode);
err = -EIO;
} else {
@@ -1563,7 +1572,8 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
goto error;
}
- if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
+ if (fuse_invalid_attr(&outarg.attr) ||
+ (inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
make_bad_inode(inode);
err = -EIO;
goto error;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index d148188cfca4..aa75e2305b75 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -989,6 +989,8 @@ void fuse_ctl_remove_conn(struct fuse_conn *fc);
*/
int fuse_valid_type(int m);
+bool fuse_invalid_attr(struct fuse_attr *attr);
+
/**
* Is current process allowed to perform filesystem operation?
*/
diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c
index 5c38b9d84c6e..6a40f75a0d25 100644
--- a/fs/fuse/readdir.c
+++ b/fs/fuse/readdir.c
@@ -184,7 +184,7 @@ static int fuse_direntplus_link(struct file *file,
if (invalid_nodeid(o->nodeid))
return -EIO;
- if (!fuse_valid_type(o->attr.mode))
+ if (fuse_invalid_attr(&o->attr))
return -EIO;
fc = get_fuse_conn(dir);