The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=300cfb96fc2253c3aff8d501d5599fcf811daa34
commit 300cfb96fc2253c3aff8d501d5599fcf811daa34 Author: Mark Johnston <[email protected]> AuthorDate: 2022-02-08 17:34:20 +0000 Commit: Mark Johnston <[email protected]> CommitDate: 2022-02-08 17:40:41 +0000 file: Make fget*() and getvnode*() consistent about initializing *fpp Most fget*() functions initialize the output parameter to NULL. Make the externally visible interface behave consistently, and make fget_unlocked_seq() private to kern_descrip.c. This fixes at least one bug in a consumer, _filemon_wrapper_openat(), which assumes that getvnode() sets the output file pointer to NULL upon an error. Reported by: [email protected] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D34190 --- sys/kern/kern_descrip.c | 12 ++++++++++-- sys/kern/vfs_syscalls.c | 2 ++ sys/sys/filedesc.h | 3 --- 3 files changed, 12 insertions(+), 5 deletions(-) diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c index d5d22ecfc522..c4cf9abde664 100644 --- a/sys/kern/kern_descrip.c +++ b/sys/kern/kern_descrip.c @@ -115,6 +115,8 @@ static void fdgrowtable(struct filedesc *fdp, int nfd); static void fdgrowtable_exp(struct filedesc *fdp, int nfd); static void fdunused(struct filedesc *fdp, int fd); static void fdused(struct filedesc *fdp, int fd); +static int fget_unlocked_seq(struct filedesc *fdp, int fd, + cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp); static int getmaxfd(struct thread *td); static u_long *filecaps_copy_prep(const struct filecaps *src); static void filecaps_copy_finish(const struct filecaps *src, @@ -2843,6 +2845,7 @@ fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, FILEDESC_LOCK_ASSERT(fdp); + *fpp = NULL; fde = fdeget_locked(fdp, fd); if (fde == NULL) { error = EBADF; @@ -3014,7 +3017,7 @@ fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsear } #endif -int +static int fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp) { @@ -3112,8 +3115,10 @@ fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, #endif fdt = fdp->fd_files; - if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) + if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) { + *fpp = NULL; return (EBADF); + } #ifdef CAPABILITIES seq = seqc_read_notmodify(fd_seqc(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; @@ -3148,6 +3153,7 @@ fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, out_fdrop: fdrop(fp, curthread); out_fallback: + *fpp = NULL; return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); } @@ -3173,6 +3179,7 @@ fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, MPASS(FILEDESC_IS_ONLY_USER(fdp)); + *fpp = NULL; if (__predict_false(fd >= fdp->fd_nfiles)) return (EBADF); @@ -3198,6 +3205,7 @@ fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, MPASS(FILEDESC_IS_ONLY_USER(fdp)); + *fpp = NULL; if (__predict_false(fd >= fdp->fd_nfiles)) return (EBADF); diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c index 3e0b96051465..5549cae570f8 100644 --- a/sys/kern/vfs_syscalls.c +++ b/sys/kern/vfs_syscalls.c @@ -4336,6 +4336,7 @@ getvnode_path(struct thread *td, int fd, cap_rights_t *rightsp, */ if (__predict_false(fp->f_vnode == NULL || fp->f_ops == &badfileops)) { fdrop(fp, td); + *fpp = NULL; return (EINVAL); } @@ -4363,6 +4364,7 @@ getvnode(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) */ if (__predict_false((*fpp)->f_ops == &path_fileops)) { fdrop(*fpp, td); + *fpp = NULL; error = EBADF; } diff --git a/sys/sys/filedesc.h b/sys/sys/filedesc.h index 6f0e74e70d3b..f003c0ff3c4b 100644 --- a/sys/sys/filedesc.h +++ b/sys/sys/filedesc.h @@ -269,10 +269,7 @@ int fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp); int fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp); - /* Return a referenced file from an unlocked descriptor. */ -int fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, - struct file **fpp, seqc_t *seqp); int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp); /* Return a file pointer without a ref. FILEDESC_IS_ONLY_USER must be true. */
