diff options
Diffstat (limited to 'fs/fcntl.c')
| -rw-r--r-- | fs/fcntl.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c index 3b01b646e528..0522e283a4f4 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/fcntl.c * @@ -562,6 +563,9 @@ static int put_compat_flock64(const struct flock *kfl, struct compat_flock64 __u { struct compat_flock64 fl; + BUILD_BUG_ON(sizeof(kfl->l_start) > sizeof(ufl->l_start)); + BUILD_BUG_ON(sizeof(kfl->l_len) > sizeof(ufl->l_len)); + memset(&fl, 0, sizeof(struct compat_flock64)); copy_flock_fields(&fl, kfl); if (copy_to_user(ufl, &fl, sizeof(struct compat_flock64))) @@ -631,9 +635,8 @@ COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, if (err) break; err = fixup_compat_flock(&flock); - if (err) - return err; - err = put_compat_flock(&flock, compat_ptr(arg)); + if (!err) + err = put_compat_flock(&flock, compat_ptr(arg)); break; case F_GETLK64: case F_OFD_GETLK: @@ -641,12 +644,8 @@ COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, if (err) break; err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); - if (err) - break; - err = fixup_compat_flock(&flock); - if (err) - return err; - err = put_compat_flock64(&flock, compat_ptr(arg)); + if (!err) + err = put_compat_flock64(&flock, compat_ptr(arg)); break; case F_SETLK: case F_SETLKW: @@ -724,7 +723,7 @@ static void send_sigio_to_task(struct task_struct *p, * 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); + int signum = READ_ONCE(fown->signum); if (!sigio_perm(p, fown, signum)) return; @@ -741,10 +740,21 @@ static void send_sigio_to_task(struct task_struct *p, si.si_signo = signum; si.si_errno = 0; si.si_code = reason; + /* + * Posix definies POLL_IN and friends to be signal + * specific si_codes for SIG_POLL. Linux extended + * these si_codes to other signals in a way that is + * ambiguous if other signals also have signal + * specific si_codes. In that case use SI_SIGIO instead + * to remove the ambiguity. + */ + if ((signum != SIGPOLL) && sig_specific_sicodes(signum)) + si.si_code = SI_SIGIO; + /* Make sure we are called with one of the POLL_* reasons, otherwise we could leak kernel stack into userspace. */ - BUG_ON((reason & __SI_MASK) != __SI_POLL); + BUG_ON((reason < POLL_IN) || ((reason - POLL_IN) >= NSIGPOLL)); if (reason - POLL_IN >= NSIGPOLL) si.si_band = ~0L; else |