6.17-stable review patch. If anyone has any objections, please let me know.
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From: Fushuai Wang wangfushuai@baidu.com
[ Upstream commit 0cc380d0e1d36b8f2703379890e90f896f68e9e8 ]
The return value of copy_to_iter() function will never be negative, it is the number of bytes copied, or zero if nothing was copied. Update the check to treat 0 as an error, and return -1 in that case.
Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Acked-by: Tom Talpey tom@talpey.com Reviewed-by: David Howells dhowells@redhat.com Signed-off-by: Fushuai Wang wangfushuai@baidu.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/smb/client/smb2ops.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 68286673afc99..328fdeecae29a 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -4653,7 +4653,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid, unsigned int pad_len; struct cifs_io_subrequest *rdata = mid->callback_data; struct smb2_hdr *shdr = (struct smb2_hdr *)buf; - int length; + size_t copied; bool use_rdma_mr = false;
if (shdr->Command != SMB2_READ) { @@ -4766,10 +4766,10 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid, } else if (buf_len >= data_offset + data_len) { /* read response payload is in buf */ WARN_ONCE(buffer, "read data can be either in buf or in buffer"); - length = copy_to_iter(buf + data_offset, data_len, &rdata->subreq.io_iter); - if (length < 0) - return length; - rdata->got_bytes = data_len; + copied = copy_to_iter(buf + data_offset, data_len, &rdata->subreq.io_iter); + if (copied == 0) + return -EIO; + rdata->got_bytes = copied; } else { /* read response payload cannot be in both buf and pages */ WARN_ONCE(1, "buf can not contain only a part of read data");