3.16.82-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Miklos Szeredi <mszeredi@xxxxxxxxxx> commit eb59bd17d2fa6e5e84fba61a5ebdea984222e6d5 upstream. 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@xxxxxxxxxx> Fixes: d8a5ba45457e ("[PATCH] FUSE - core") Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- fs/fuse/dir.c | 24 +++++++++++++++++------- fs/fuse/fuse_i.h | 2 ++ 2 files changed, 19 insertions(+), 7 deletions(-) --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -250,7 +250,8 @@ static int fuse_dentry_revalidate(struct spin_unlock(&fc->lock); } kfree(forget); - if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) + if (err || fuse_invalid_attr(&outarg.attr) || + (outarg.attr.mode ^ inode->i_mode) & S_IFMT) goto invalid; fuse_change_attributes(inode, &outarg.attr, @@ -295,6 +296,12 @@ 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, struct qstr *name, struct fuse_entry_out *outarg, struct inode **inode) { @@ -334,7 +341,7 @@ int fuse_lookup_name(struct super_block 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, @@ -464,7 +471,8 @@ static int fuse_create_open(struct inode 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; fuse_put_request(fc, req); @@ -580,7 +588,7 @@ static int create_new_entry(struct fuse_ 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) @@ -971,7 +979,8 @@ static int fuse_do_getattr(struct inode err = req->out.h.error; fuse_put_request(fc, req); 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 { @@ -1282,7 +1291,7 @@ static int fuse_direntplus_link(struct f 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); @@ -1794,7 +1803,8 @@ int fuse_do_setattr(struct dentry *dentr 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; --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -828,6 +828,8 @@ void fuse_ctl_remove_conn(struct fuse_co */ int fuse_valid_type(int m); +bool fuse_invalid_attr(struct fuse_attr *attr); + /** * Is current process allowed to perform filesystem operation? */