diff options
Diffstat (limited to 'fs/anon_inodes.c')
| -rw-r--r-- | fs/anon_inodes.c | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 42bd1cb7c9cd..e51e7d88980a 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -24,10 +24,51 @@ #include <linux/uaccess.h> +#include "internal.h" + static struct vfsmount *anon_inode_mnt __ro_after_init; static struct inode *anon_inode_inode __ro_after_init; /* + * User space expects anonymous inodes to have no file type in st_mode. + * + * In particular, 'lsof' has this legacy logic: + * + * type = s->st_mode & S_IFMT; + * switch (type) { + * ... + * case 0: + * if (!strcmp(p, "anon_inode")) + * Lf->ntype = Ntype = N_ANON_INODE; + * + * to detect our old anon_inode logic. + * + * Rather than mess with our internal sane inode data, just fix it + * up here in getattr() by masking off the format bits. + */ +int anon_inode_getattr(struct mnt_idmap *idmap, const struct path *path, + struct kstat *stat, u32 request_mask, + unsigned int query_flags) +{ + struct inode *inode = d_inode(path->dentry); + + generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); + stat->mode &= ~S_IFMT; + return 0; +} + +int anon_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + struct iattr *attr) +{ + return -EOPNOTSUPP; +} + +static const struct inode_operations anon_inode_operations = { + .getattr = anon_inode_getattr, + .setattr = anon_inode_setattr, +}; + +/* * anon_inodefs_dname() is called from d_path(). */ static char *anon_inodefs_dname(struct dentry *dentry, char *buffer, int buflen) @@ -45,6 +86,8 @@ static int anon_inodefs_init_fs_context(struct fs_context *fc) struct pseudo_fs_context *ctx = init_pseudo(fc, ANON_INODE_FS_MAGIC); if (!ctx) return -ENOMEM; + fc->s_iflags |= SB_I_NOEXEC; + fc->s_iflags |= SB_I_NODEV; ctx->dops = &anon_inodefs_dentry_operations; return 0; } @@ -60,14 +103,15 @@ static struct inode *anon_inode_make_secure_inode( const struct inode *context_inode) { struct inode *inode; - const struct qstr qname = QSTR_INIT(name, strlen(name)); int error; inode = alloc_anon_inode(anon_inode_mnt->mnt_sb); if (IS_ERR(inode)) return inode; inode->i_flags &= ~S_PRIVATE; - error = security_inode_init_security_anon(inode, &qname, context_inode); + inode->i_op = &anon_inode_operations; + error = security_inode_init_security_anon(inode, &QSTR(name), + context_inode); if (error) { iput(inode); return ERR_PTR(error); @@ -313,6 +357,7 @@ static int __init anon_inode_init(void) anon_inode_inode = alloc_anon_inode(anon_inode_mnt->mnt_sb); if (IS_ERR(anon_inode_inode)) panic("anon_inode_init() inode allocation failed (%ld)\n", PTR_ERR(anon_inode_inode)); + anon_inode_inode->i_op = &anon_inode_operations; return 0; } |