Bug: After mounting the cifs fs, it complains with Resource temporarily unavailable messages.
[root@vm1 xfstests-dev]# ./check -g quick -s smb3 TEST_DEV=//<SERVER_IP>/TEST is mounted but not a type cifs filesystem [root@vm1 xfstests-dev]# df df: /mnt/test: Resource temporarily unavailable
Paul's analysis of the bug:
Bug is related to an off-by-one in smb2_set_next_command() when the client attempts to pad SMB2_QUERY_INFO request -- since it isn't 8 byte aligned -- even though smb2_query_info_compound() doesn't provide an extra iov for such padding.
v5.10.y doesn't have
eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays")
and the commit does
if (unlikely(check_add_overflow(input_len, sizeof(*req), &len) || len > CIFSMaxBufSize)) return -EINVAL;
so sizeof(*req) will wrongly include the extra byte from smb2_query_info_req::Buffer making @len unaligned and therefore causing OOB in smb2_set_next_command().
Fixes: 203a412e52b5 ("smb: client: fix OOB in SMB2_query_info_init()") Suggested-by: Paulo Alcantara pc@manguebit.com Signed-off-by: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com --- This patch is only for v5.10.y stable kernel. I have tested the patched kernel, after mounting it doesn't become unavailable.
Context: [1] https://lore.kernel.org/all/CAH2r5mv2ipr4KJfMDXwHgq9L+kGdnRd1C2svcM=PCoDjA7u...
Note to Greg: This is alternative way to fix by not taking commit eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays"). before applying this patch a patch in the queue needs to be removed: https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree...
As I have stated in [1] I am unsure the which is the best way, but this commit eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays") is not in 5.15.y so I think we shouldn't queue it in 5.10.y --- fs/cifs/smb2pdu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 76679dc4e6328..514e2cf44d951 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -3379,7 +3379,7 @@ SMB2_query_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
iov[0].iov_base = (char *)req; /* 1 for Buffer */ - iov[0].iov_len = len; + iov[0].iov_len = len - 1; return 0; }
29.01.2024 08:43, Harshit Mogalapalli wrote:
This patch is only for v5.10.y stable kernel. I have tested the patched kernel, after mounting it doesn't become unavailable.
Context: [1] https://lore.kernel.org/all/CAH2r5mv2ipr4KJfMDXwHgq9L+kGdnRd1C2svcM=PCoDjA7u...
Note to Greg: This is alternative way to fix by not taking commit eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays"). before applying this patch a patch in the queue needs to be removed: https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree...
Maybe I don't understand something, but isn't there a goal when fixing bugs to keep the code of stable branches with upstream code as much as possible? Otherwise, the following fixes will not be compatible..
Hi Kovalev,
On 29/01/24 1:49 pm, kovalev@altlinux.org wrote:
29.01.2024 08:43, Harshit Mogalapalli wrote:
This patch is only for v5.10.y stable kernel. I have tested the patched kernel, after mounting it doesn't become unavailable.
Context: [1] https://lore.kernel.org/all/CAH2r5mv2ipr4KJfMDXwHgq9L+kGdnRd1C2svcM=PCoDjA7u...
Note to Greg: This is alternative way to fix by not taking commit eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays"). before applying this patch a patch in the queue needs to be removed: https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree...
Maybe I don't understand something, but isn't there a goal when fixing bugs to keep the code of stable branches with upstream code as much as possible? Otherwise, the following fixes will not be compatible..
I agree, but at the same time we also should observe this: eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays") is not in 5.15.y so we probably shouldn't queue it up for 5.10.y.
Ref from stable kernel rules document: https://www.kernel.org/doc/html/v6.7/process/stable-kernel-rules.html#:~:tex.... (Just above Option 1 description)
Thanks, Harshit
On Mon, Jan 29, 2024 at 09:57:40PM +0530, Harshit Mogalapalli wrote:
Hi Kovalev,
On 29/01/24 1:49 pm, kovalev@altlinux.org wrote:
29.01.2024 08:43, Harshit Mogalapalli wrote:
This patch is only for v5.10.y stable kernel. I have tested the patched kernel, after mounting it doesn't become unavailable.
Context: [1] https://lore.kernel.org/all/CAH2r5mv2ipr4KJfMDXwHgq9L+kGdnRd1C2svcM=PCoDjA7u...
Note to Greg: This is alternative way to fix by not taking commit eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays"). before applying this patch a patch in the queue needs to be removed: https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree...
Maybe I don't understand something, but isn't there a goal when fixing bugs to keep the code of stable branches with upstream code as much as possible? Otherwise, the following fixes will not be compatible..
I agree, but at the same time we also should observe this: eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays") is not in 5.15.y so we probably shouldn't queue it up for 5.10.y.
It is queued up for 5.10, but not 5.15 for some reason?
confused,
greg k-h
On 29/01/24 10:07 pm, Greg KH wrote:
On Mon, Jan 29, 2024 at 09:57:40PM +0530, Harshit Mogalapalli wrote:
Hi Kovalev,
On 29/01/24 1:49 pm, kovalev@altlinux.org wrote:
29.01.2024 08:43, Harshit Mogalapalli wrote:
This patch is only for v5.10.y stable kernel. I have tested the patched kernel, after mounting it doesn't become unavailable.
Context: [1] https://lore.kernel.org/all/CAH2r5mv2ipr4KJfMDXwHgq9L+kGdnRd1C2svcM=PCoDjA7u...
Note to Greg: This is alternative way to fix by not taking commit eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays"). before applying this patch a patch in the queue needs to be removed: https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree...
Maybe I don't understand something, but isn't there a goal when fixing bugs to keep the code of stable branches with upstream code as much as possible? Otherwise, the following fixes will not be compatible..
I agree, but at the same time we also should observe this: eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays") is not in 5.15.y so we probably shouldn't queue it up for 5.10.y.
Hi Greg,
It is queued up for 5.10, but not 5.15 for some reason?
Context: https://lore.kernel.org/all/472d92aa-1b49-43c9-a91f-80dfc8f25ad3@oracle.com/
I think the above commit eb3e28c1e89b ("smb3: Replace smb2pdu 1-element arrays with flex-arrays") got queued up from the above backport.
I did try applying on 5.15.y but I noticed many conflicts, so I asked which is the preferred way: 1. Resolving conflicts by backporting above commit(flex-arrays one), which touches more code. 2. Or go with one line change.
I thought one liner is is a simpler change although it is not a upstream commit. Steve French also agreed with approach 2(which Paul suggested here [1], so I made patch(approach 2) for 5.15.y and 5.10.y and tested both after patching, they work.
[1] https://lore.kernel.org/all/446860c571d0699ed664175262a9e84b@manguebit.com/
Thanks, Harshit
confused,
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg KH -
Harshit Mogalapalli -
kovalevï¼ altlinux.org