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FAILED: patch "[PATCH] smb: client: fix potential OOBs in smb2_parse_contexts()" failed to apply to 6.1-stable tree

PATCH [email protected] 1 participant 1 message Dec 18, 2023

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The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x af1689a9b7701d9907dfc84d2a4b57c4bc907144
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023121834-semisoft-snarl-49ad@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

af1689a9b770 ("smb: client: fix potential OOBs in smb2_parse_contexts()") 5c86919455c1 ("smb: client: fix use-after-free in smb2_query_info_compound()") 81ba10959970 ("smb: client: prevent new fids from being removed by laundromat") e95f3f744650 ("smb: client: make laundromat a delayed worker")
2da338ff752a ("smb3: do not start laundromat thread when dir leases disabled") 238b351d0935 ("smb3: allow controlling length of time directory entries are cached with dir leases") d14de8067e3f ("cifs: Add a laundromat thread for cached directories")
38c8a9a52082 ("smb: move client and server files to common directory fs/smb") be4fde79812f ("cifs: fix dentry lookups in directory handle cache")
df57109bd50b ("cifs: use tcon allocation functions even for dummy tcon") 8e843bf38f7b ("cifs: return a single-use cfid if we did not get a lease") 66d45ca1350a ("cifs: Check the lease context if we actually got a lease") abdb1742a312 ("cifs: get rid of mount options string parsing")
9fd29a5bae6e ("cifs: use fs_context for automounts")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From af1689a9b7701d9907dfc84d2a4b57c4bc907144 Mon Sep 17 00:00:00 2001
From: Paulo Alcantara <[email protected]>
Date: Mon, 11 Dec 2023 10:26:41 -0300
Subject: [PATCH] smb: client: fix potential OOBs in smb2_parse_contexts()

Validate offsets and lengths before dereferencing create contexts in smb2_parse_contexts().

This fixes following oops when accessing invalid create contexts from server:

  BUG: unable to handle page fault for address: ffff8881178d8cc3
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 4a01067 P4D 4a01067 PUD 0
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 3 PID: 1736 Comm: mount.cifs Not tainted 6.7.0-rc4 #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
  RIP: 0010:smb2_parse_contexts+0xa0/0x3a0 [cifs]
  Code: f8 10 75 13 48 b8 93 ad 25 50 9c b4 11 e7 49 39 06 0f 84 d2 00
  00 00 8b 45 00 85 c0 74 61 41 29 c5 48 01 c5 41 83 fd 0f 76 55 <0f> b7
  7d 04 0f b7 45 06 4c 8d 74 3d 00 66 83 f8 04 75 bc ba 04 00
  RSP: 0018:ffffc900007939e0 EFLAGS: 00010216
  RAX: ffffc90000793c78 RBX: ffff8880180cc000 RCX: ffffc90000793c90
  RDX: ffffc90000793cc0 RSI: ffff8880178d8cc0 RDI: ffff8880180cc000
  RBP: ffff8881178d8cbf R08: ffffc90000793c22 R09: 0000000000000000
  R10: ffff8880180cc000 R11: 0000000000000024 R12: 0000000000000000
  R13: 0000000000000020 R14: 0000000000000000 R15: ffffc90000793c22
  FS: 00007f873753cbc0(0000) GS:ffff88806bc00000(0000)
  knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffff8881178d8cc3 CR3: 00000000181ca000 CR4: 0000000000750ef0
  PKRU: 55555554
  Call Trace:
   <TASK>
   ? __die+0x23/0x70
   ? page_fault_oops+0x181/0x480
   ? search_module_extables+0x19/0x60
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? exc_page_fault+0x1b6/0x1c0
   ? asm_exc_page_fault+0x26/0x30
   ? smb2_parse_contexts+0xa0/0x3a0 [cifs]
   SMB2_open+0x38d/0x5f0 [cifs]
   ? smb2_is_path_accessible+0x138/0x260 [cifs]
   smb2_is_path_accessible+0x138/0x260 [cifs]
   cifs_is_path_remote+0x8d/0x230 [cifs]
   cifs_mount+0x7e/0x350 [cifs]
   cifs_smb3_do_mount+0x128/0x780 [cifs]
   smb3_get_tree+0xd9/0x290 [cifs]
   vfs_get_tree+0x2c/0x100
   ? capable+0x37/0x70
   path_mount+0x2d7/0xb80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? _raw_spin_unlock_irqrestore+0x44/0x60
   __x64_sys_mount+0x11a/0x150
   do_syscall_64+0x47/0xf0
   entry_SYSCALL_64_after_hwframe+0x6f/0x77
  RIP: 0033:0x7f8737657b1e
fs/smb/client/cached_dir.c +12 -5
index 59f6b8e32cc9..d64a306a414b 100644
@@ -291,16 +291,23 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
 #endif /* CIFS_DEBUG2 */
 
-	rc = -EINVAL;
+
 	if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
+		spin_unlock(&cfids->cfid_list_lock);
+		rc = -EINVAL;
+		goto oshr_free;
+	}
+
+	rc = smb2_parse_contexts(server, rsp_iov,
+				 &oparms.fid->epoch,
+				 oparms.fid->lease_key,
+				 &oplock, NULL, NULL);
+	if (rc) {
 		spin_unlock(&cfids->cfid_list_lock);
 		goto oshr_free;
 	}
 
-	smb2_parse_contexts(server, o_rsp,
-			    &oparms.fid->epoch,
-			    oparms.fid->lease_key, &oplock,
-			    NULL, NULL);
+	rc = -EINVAL;
 	if (!(oplock & SMB2_LEASE_READ_CACHING_HE)) {
 		spin_unlock(&cfids->cfid_list_lock);
 		goto oshr_free;
fs/smb/client/smb2pdu.c +57 -38

127 lines not on this page · raw message

fs/smb/client/smb2proto.h +7 -5
index 46eff9ec302a..0e371f7e2854 100644
@@ -251,11 +251,13 @@ extern int smb3_validate_negotiate(const unsigned int, struct cifs_tcon *);
 
 extern enum securityEnum smb2_select_sectype(struct TCP_Server_Info *,
 					enum securityEnum);
-extern void smb2_parse_contexts(struct TCP_Server_Info *server,
-				struct smb2_create_rsp *rsp,
-				unsigned int *epoch, char *lease_key,
-				__u8 *oplock, struct smb2_file_all_info *buf,
-				struct create_posix_rsp *posix);
+int smb2_parse_contexts(struct TCP_Server_Info *server,
+			struct kvec *rsp_iov,
+			unsigned int *epoch,
+			char *lease_key, __u8 *oplock,
+			struct smb2_file_all_info *buf,
+			struct create_posix_rsp *posix);
+
 extern int smb3_encryption_required(const struct cifs_tcon *tcon);
 extern int smb2_validate_iov(unsigned int offset, unsigned int buffer_length,
 			     struct kvec *iov, unsigned int min_buf_size);