Stable patch for 5.15.x

Commit Message

Trond Myklebust Oct. 29, 2022, 2:58 a.m. UTC

Hi Greg / Sasha,

Can we please pull commit c3ed222745d9 ("NFSv4: Fix free of
uninitialized nfs4_label on referral lookup.") into the 5.15.x tree? As
far as I can tell, it should apply cleanly on top of v5.15.75.

Unfortunately, that commit also contains a bug, which requires us to
pull in commit 4f40a5b55446 ("NFSv4: Add an fattr allocation to
_nfs4_discover_trunking()"), which does not apply cleanly. I've
attached a backported version to this email.

I'm seeing the Oops that this commit fixes when I do a NFSv4.2 mount
from a NFS client running a 5.15.75 kernel against a server that has
referrals configured. The reason is that commit d755ad8dc752 ("NFS:
Create a new nfs_alloc_fattr_with_label() function") got pulled into
v5.15.46 apparently as part of a dependency.

Thanks
 Trond

Comments

Greg KH Oct. 30, 2022, 10:54 a.m. UTC | #1

On Fri, Oct 28, 2022 at 10:58:05PM -0400, Trond Myklebust wrote:
> Hi Greg / Sasha,
> 
> Can we please pull commit c3ed222745d9 ("NFSv4: Fix free of
> uninitialized nfs4_label on referral lookup.") into the 5.15.x tree? As
> far as I can tell, it should apply cleanly on top of v5.15.75.
> 
> Unfortunately, that commit also contains a bug, which requires us to
> pull in commit 4f40a5b55446 ("NFSv4: Add an fattr allocation to
> _nfs4_discover_trunking()"), which does not apply cleanly. I've
> attached a backported version to this email.
> 
> I'm seeing the Oops that this commit fixes when I do a NFSv4.2 mount
> from a NFS client running a 5.15.75 kernel against a server that has
> referrals configured. The reason is that commit d755ad8dc752 ("NFS:
> Create a new nfs_alloc_fattr_with_label() function") got pulled into
> v5.15.46 apparently as part of a dependency.

Both now queued up, thanks.

greg k-h

Patch

From 80b979c1bec21a76913c056ab0a024e41eab0857 Mon Sep 17 00:00:00 2001
From: Scott Mayhew <[e-mail]>
Date: Mon, 27 Jun 2022 17:31:29 -0400
Subject: [PATCH] NFSv4: Add an fattr allocation to _nfs4_discover_trunking()

This was missed in c3ed222745d9 ("NFSv4: Fix free of uninitialized
nfs4_label on referral lookup.") and causes a panic when mounting
with '-o trunkdiscovery':

PID: 1604   TASK: ffff93dac3520000  CPU: 3   COMMAND: "mount.nfs"
 #0 [ffffb79140f738f8] machine_kexec at ffffffffaec64bee
 #1 [ffffb79140f73950] __crash_kexec at ffffffffaeda67fd
 #2 [ffffb79140f73a18] crash_kexec at ffffffffaeda76ed
 #3 [ffffb79140f73a30] oops_end at ffffffffaec2658d
 #4 [ffffb79140f73a50] general_protection at ffffffffaf60111e
    [exception RIP: nfs_fattr_init+0x5]
    RIP: ffffffffc0c18265  RSP: ffffb79140f73b08  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff93dac304a800  RCX: 0000000000000000
    RDX: ffffb79140f73bb0  RSI: ffff93dadc8cbb40  RDI: d03ee11cfaf6bd50
    RBP: ffffb79140f73be8   R8: ffffffffc0691560   R9: 0000000000000006
    R10: ffff93db3ffd3df8  R11: 0000000000000000  R12: ffff93dac4040000
    R13: ffff93dac2848e00  R14: ffffb79140f73b60  R15: ffffb79140f73b30
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #5 [ffffb79140f73b08] _nfs41_proc_get_locations at ffffffffc0c73d53 [nfsv4]
 #6 [ffffb79140f73bf0] nfs4_proc_get_locations at ffffffffc0c83e90 [nfsv4]
 #7 [ffffb79140f73c60] nfs4_discover_trunking at ffffffffc0c83fb7 [nfsv4]
 #8 [ffffb79140f73cd8] nfs_probe_fsinfo at ffffffffc0c0f95f [nfs]
 #9 [ffffb79140f73da0] nfs_probe_server at ffffffffc0c1026a [nfs]
    RIP: 00007f6254fce26e  RSP: 00007ffc69496ac8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 0000000000000000  RCX: 00007f6254fce26e
    RDX: 00005600220a82a0  RSI: 00005600220a64d0  RDI: 00005600220a6520
    RBP: 00007ffc69496c50   R8: 00005600220a8710   R9: 003035322e323231
    R10: 0000000000000000  R11: 0000000000000246  R12: 00007ffc69496c50
    R13: 00005600220a8440  R14: 0000000000000010  R15: 0000560020650ef9
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

Fixes: c3ed222745d9 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.")
Signed-off-by: Scott Mayhew <[e-mail]>
Signed-off-by: Anna Schumaker <[e-mail]>
(cherry picked from commit 4f40a5b5544618b096d1611a18219dd91fd57f80)
Signed-off-by: Trond Myklebust <[e-mail]>
---
 fs/nfs/nfs4proc.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index c86efd36dea8..b42e332775fe 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3981,18 +3981,23 @@  static int _nfs4_discover_trunking(struct nfs_server *server,
 	}
 
 	page = alloc_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
 	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
-	if (page == NULL || locations == NULL)
-		goto out;
+	if (!locations)
+		goto out_free;
+	locations->fattr = nfs_alloc_fattr();
+	if (!locations->fattr)
+		goto out_free_2;
 
 	status = nfs4_proc_get_locations(server, fhandle, locations, page,
 					 cred);
-	if (status)
-		goto out;
-out:
-	if (page)
-		__free_page(page);
+
+	kfree(locations->fattr);
+out_free_2:
 	kfree(locations);
+out_free:
+	__free_page(page);
 	return status;
 }
 
-- 
2.37.3