git: c6c0b631fa26 - stable/13 - aio: Fix up the opcode in aiocb32_copyin()

From: John Baldwin <jhb_at_FreeBSD.org>
Date: Wed, 06 Sep 2023 21:56:34 UTC
The branch stable/13 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=c6c0b631fa26afc22c8476f577728d65a003e801

commit c6c0b631fa26afc22c8476f577728d65a003e801
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2021-09-11 16:55:32 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2023-09-06 21:56:09 +0000

    aio: Fix up the opcode in aiocb32_copyin()
    
    With lio_listio(2), the opcode is specified by userspace rather than
    being hard-coded by the system call (e.g., aio_readv() -> LIO_READV).
    kern_lio_listio() calls aio_aqueue() with an opcode of LIO_NOP, which
    gets fixed up when the aiocb is copied in.
    
    When copying in a job request for vectored I/O, we need to dynamically
    allocate a uio to wrap an iovec.  So aiocb_copyin() needs to get the
    opcode from the aiocb and then decide whether an allocation is required.
    We failed to do this in the COMPAT_FREEBSD32 case.  Fix it.
    
    Reported by:    syzbot+27eab6f2c2162f2885ee@syzkaller.appspotmail.com
    Reviewed by:    kib, asomers
    Fixes:  f30a1ae8d529 ("lio_listio(2):  Allow LIO_READV and LIO_WRITEV.")
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D31914
    
    (cherry picked from commit 2884918c73389bebfc8025bfb267adae086ee0bd)
---
 sys/kern/vfs_aio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index 02014ceefdf5..5ad912ea38c4 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -2829,6 +2829,8 @@ aiocb32_copyin(struct aiocb *ujob, struct kaiocb *kjob, int type)
 	CP(job32, *kcb, aio_fildes);
 	CP(job32, *kcb, aio_offset);
 	CP(job32, *kcb, aio_lio_opcode);
+	if (type == LIO_NOP)
+		type = kcb->aio_lio_opcode;
 	if (type & LIO_VECTORED) {
 		iov32 = PTRIN(job32.aio_iov);
 		CP(job32, *kcb, aio_iovcnt);