diff options
Diffstat (limited to 'fs/fcntl.c')
| -rw-r--r-- | fs/fcntl.c | 33 |
1 files changed, 21 insertions, 12 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index 1ad703150de..a040b764f8e 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -198,15 +198,19 @@ static int setfl(int fd, struct file * filp, unsigned long arg) } static void f_modown(struct file *filp, struct pid *pid, enum pid_type type, - uid_t uid, uid_t euid, int force) + int force) { write_lock_irq(&filp->f_owner.lock); if (force || !filp->f_owner.pid) { put_pid(filp->f_owner.pid); filp->f_owner.pid = get_pid(pid); filp->f_owner.pid_type = type; - filp->f_owner.uid = uid; - filp->f_owner.euid = euid; + + if (pid) { + const struct cred *cred = current_cred(); + filp->f_owner.uid = cred->uid; + filp->f_owner.euid = cred->euid; + } } write_unlock_irq(&filp->f_owner.lock); } @@ -214,14 +218,13 @@ 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, cred->uid, cred->euid, force); + f_modown(filp, pid, type, force); return 0; } EXPORT_SYMBOL(__f_setown); @@ -247,7 +250,7 @@ EXPORT_SYMBOL(f_setown); void f_delown(struct file *filp) { - f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1); + f_modown(filp, NULL, PIDTYPE_PID, 1); } pid_t f_getown(struct file *filp) @@ -425,14 +428,20 @@ static inline int sigio_perm(struct task_struct *p, } static void send_sigio_to_task(struct task_struct *p, - struct fown_struct *fown, + struct fown_struct *fown, int fd, int reason) { - if (!sigio_perm(p, fown, fown->signum)) + /* + * F_SETSIG can change ->signum lockless in parallel, make + * sure we read it once and use the same value throughout. + */ + int signum = ACCESS_ONCE(fown->signum); + + if (!sigio_perm(p, fown, signum)) return; - switch (fown->signum) { + switch (signum) { siginfo_t si; default: /* Queue a rt signal with the appropriate fd as its @@ -441,7 +450,7 @@ static void send_sigio_to_task(struct task_struct *p, delivered even if we can't queue. Failure to queue in this case _should_ be reported; we fall back to SIGIO in that case. --sct */ - si.si_signo = fown->signum; + si.si_signo = signum; si.si_errno = 0; si.si_code = reason; /* Make sure we are called with one of the POLL_* @@ -453,7 +462,7 @@ static void send_sigio_to_task(struct task_struct *p, else si.si_band = band_table[reason - POLL_IN]; si.si_fd = fd; - if (!group_send_sig_info(fown->signum, &si, p)) + if (!group_send_sig_info(signum, &si, p)) break; /* fall-through: fall back on the old plain SIGIO signal */ case 0: |