diff options
| author | dillon <dillon@FreeBSD.org> | 2000-11-18 21:01:04 +0000 |
|---|---|---|
| committer | dillon <dillon@FreeBSD.org> | 2000-11-18 21:01:04 +0000 |
| commit | 15a44d16ca10bf52da55462560c345940cd19b38 (patch) | |
| tree | 8d59044fc11c59a31ff7d5eb596055dcd4bfa68c /sys/kern/sys_pipe.c | |
| parent | fd59970ee1df44d623fb078d21e32c352d64b79f (diff) | |
| download | FreeBSD-src-15a44d16ca10bf52da55462560c345940cd19b38.zip FreeBSD-src-15a44d16ca10bf52da55462560c345940cd19b38.tar.gz | |
This patchset fixes a large number of file descriptor race conditions.
Pre-rfork code assumed inherent locking of a process's file descriptor
array. However, with the advent of rfork() the file descriptor table
could be shared between processes. This patch closes over a dozen
serious race conditions related to one thread manipulating the table
(e.g. closing or dup()ing a descriptor) while another is blocked in
an open(), close(), fcntl(), read(), write(), etc...
PR: kern/11629
Discussed with: Alexander Viro <viro@math.psu.edu>
Diffstat (limited to 'sys/kern/sys_pipe.c')
| -rw-r--r-- | sys/kern/sys_pipe.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c index 7600ffd..4c505e7 100644 --- a/sys/kern/sys_pipe.c +++ b/sys/kern/sys_pipe.c @@ -185,6 +185,7 @@ pipe(p, uap) error = falloc(p, &rf, &fd); if (error) goto free2; + fhold(rf); p->p_retval[0] = fd; rf->f_flag = FREAD | FWRITE; rf->f_type = DTYPE_PIPE; @@ -201,11 +202,15 @@ pipe(p, uap) rpipe->pipe_peer = wpipe; wpipe->pipe_peer = rpipe; + fdrop(rf, p); return (0); free3: - fdp->fd_ofiles[p->p_retval[0]] = 0; - ffree(rf); + if (fdp->fd_ofiles[p->p_retval[0]] == rf) { + fdp->fd_ofiles[p->p_retval[0]] = NULL; + fdrop(rf, p); + } + fdrop(rf, p); free2: (void)pipeclose(wpipe); (void)pipeclose(rpipe); |
