From 80ff00172407e0aad4b10b94ef0816fc3e7813cb Mon Sep 17 00:00:00 2001 From: Yao Liu Date: Mon, 28 Jan 2019 19:44:14 +0800 Subject: nfs: Fix NULL pointer dereference of dev_name There is a NULL pointer dereference of dev_name in nfs_parse_devname() The oops looks something like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 ... RIP: 0010:nfs_fs_mount+0x3b6/0xc20 [nfs] ... Call Trace: ? ida_alloc_range+0x34b/0x3d0 ? nfs_clone_super+0x80/0x80 [nfs] ? nfs_free_parsed_mount_data+0x60/0x60 [nfs] mount_fs+0x52/0x170 ? __init_waitqueue_head+0x3b/0x50 vfs_kern_mount+0x6b/0x170 do_mount+0x216/0xdc0 ksys_mount+0x83/0xd0 __x64_sys_mount+0x25/0x30 do_syscall_64+0x65/0x220 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fix this by adding a NULL check on dev_name Signed-off-by: Yao Liu Signed-off-by: Anna Schumaker --- fs/nfs/super.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs') diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 22ce3c8a2f46..0570391eaa16 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1895,6 +1895,11 @@ static int nfs_parse_devname(const char *dev_name, size_t len; char *end; + if (unlikely(!dev_name || !*dev_name)) { + dfprintk(MOUNT, "NFS: device name not specified\n"); + return -EINVAL; + } + /* Is the host name protected with square brakcets? */ if (*dev_name == '[') { end = strchr(++dev_name, ']'); -- cgit v1.2.3 From 8fc75bed96bb94e23ca51bd9be4daf65c57697bf Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 29 Jan 2019 15:52:55 -0500 Subject: NFS: Fix up return value on fatal errors in nfs_page_async_flush() Ensure that we return the fatal error value that caused us to exit nfs_page_async_flush(). Fixes: c373fff7bd25 ("NFSv4: Don't special case "launder"") Signed-off-by: Trond Myklebust Cc: stable@vger.kernel.org # v4.12+ Reviewed-by: Benjamin Coddington Signed-off-by: Anna Schumaker --- fs/nfs/write.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 5a0bbf917a32..f12cb31a41e5 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -621,11 +621,12 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, nfs_set_page_writeback(page); WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags)); - ret = 0; + ret = req->wb_context->error; /* If there is a fatal error that covers this write, just exit */ - if (nfs_error_is_fatal_on_server(req->wb_context->error)) + if (nfs_error_is_fatal_on_server(ret)) goto out_launder; + ret = 0; if (!nfs_pageio_add_request(pgio, req)) { ret = pgio->pg_error; /* @@ -635,9 +636,9 @@ static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, nfs_context_set_write_error(req->wb_context, ret); if (nfs_error_is_fatal_on_server(ret)) goto out_launder; - } + } else + ret = -EAGAIN; nfs_redirty_request(req); - ret = -EAGAIN; } else nfs_add_stats(page_file_mapping(page)->host, NFSIOS_WRITEPAGES, 1); -- cgit v1.2.3