diff options
Diffstat (limited to 'fs/fcntl.c')
| -rw-r--r-- | fs/fcntl.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index ac4f7db9f13..cdc14194672 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -19,6 +19,7 @@ #include <linux/signal.h> #include <linux/rcupdate.h> #include <linux/pid_namespace.h> +#include <linux/smp_lock.h> #include <asm/poll.h> #include <asm/siginfo.h> @@ -175,6 +176,11 @@ static int setfl(int fd, struct file * filp, unsigned long arg) if (error) return error; + /* + * We still need a lock here for now to keep multiple FASYNC calls + * from racing with each other. + */ + lock_kernel(); if ((arg ^ filp->f_flags) & FASYNC) { if (filp->f_op && filp->f_op->fasync) { error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0); @@ -185,6 +191,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg) filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK); out: + unlock_kernel(); return error; } @@ -205,13 +212,14 @@ static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, int __f_setown(struct file *filp, struct pid *pid, enum pid_type type, int force) { + const struct cred *cred = current_cred(); int err; err = security_file_set_fowner(filp); if (err) return err; - f_modown(filp, pid, type, current->uid, current->euid, force); + f_modown(filp, pid, type, cred->uid, cred->euid, force); return 0; } EXPORT_SYMBOL(__f_setown); @@ -400,10 +408,17 @@ static const long band_table[NSIGPOLL] = { static inline int sigio_perm(struct task_struct *p, struct fown_struct *fown, int sig) { - return (((fown->euid == 0) || - (fown->euid == p->suid) || (fown->euid == p->uid) || - (fown->uid == p->suid) || (fown->uid == p->uid)) && - !security_file_send_sigiotask(p, fown, sig)); + const struct cred *cred; + int ret; + + rcu_read_lock(); + cred = __task_cred(p); + ret = ((fown->euid == 0 || + fown->euid == cred->suid || fown->euid == cred->uid || + fown->uid == cred->suid || fown->uid == cred->uid) && + !security_file_send_sigiotask(p, fown, sig)); + rcu_read_unlock(); + return ret; } static void send_sigio_to_task(struct task_struct *p, |