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Paul Aurich 7afb867336 smb: Don't leak cfid when reconnect races with open_cached_dir
open_cached_dir() may either race with the tcon reconnection even before
compound_send_recv() or directly trigger a reconnection via
SMB2_open_init() or SMB_query_info_init().

The reconnection process invokes invalidate_all_cached_dirs() via
cifs_mark_open_files_invalid(), which removes all cfids from the
cfids->entries list but doesn't drop a ref if has_lease isn't true. This
results in the currently-being-constructed cfid not being on the list,
but still having a refcount of 2. It leaks if returned from
open_cached_dir().

Fix this by setting cfid->has_lease when the ref is actually taken; the
cfid will not be used by other threads until it has a valid time.

Addresses these kmemleaks:

unreferenced object 0xffff8881090c4000 (size 1024):
  comm "bash", pid 1860, jiffies 4295126592
  hex dump (first 32 bytes):
    00 01 00 00 00 00 ad de 22 01 00 00 00 00 ad de  ........".......
    00 ca 45 22 81 88 ff ff f8 dc 4f 04 81 88 ff ff  ..E"......O.....
  backtrace (crc 6f58c20f):
    [<ffffffff8b895a1e>] __kmalloc_cache_noprof+0x2be/0x350
    [<ffffffff8bda06e3>] open_cached_dir+0x993/0x1fb0
    [<ffffffff8bdaa750>] cifs_readdir+0x15a0/0x1d50
    [<ffffffff8b9a853f>] iterate_dir+0x28f/0x4b0
    [<ffffffff8b9a9aed>] __x64_sys_getdents64+0xfd/0x200
    [<ffffffff8cf6da05>] do_syscall_64+0x95/0x1a0
    [<ffffffff8d00012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
unreferenced object 0xffff8881044fdcf8 (size 8):
  comm "bash", pid 1860, jiffies 4295126592
  hex dump (first 8 bytes):
    00 cc cc cc cc cc cc cc                          ........
  backtrace (crc 10c106a9):
    [<ffffffff8b89a3d3>] __kmalloc_node_track_caller_noprof+0x363/0x480
    [<ffffffff8b7d7256>] kstrdup+0x36/0x60
    [<ffffffff8bda0700>] open_cached_dir+0x9b0/0x1fb0
    [<ffffffff8bdaa750>] cifs_readdir+0x15a0/0x1d50
    [<ffffffff8b9a853f>] iterate_dir+0x28f/0x4b0
    [<ffffffff8b9a9aed>] __x64_sys_getdents64+0xfd/0x200
    [<ffffffff8cf6da05>] do_syscall_64+0x95/0x1a0
    [<ffffffff8d00012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e

And addresses these BUG splats when unmounting the SMB filesystem:

BUG: Dentry ffff888140590ba0{i=1000000000080,n=/}  still in use (2) [unmount of cifs cifs]
WARNING: CPU: 3 PID: 3433 at fs/dcache.c:1536 umount_check+0xd0/0x100
Modules linked in:
CPU: 3 UID: 0 PID: 3433 Comm: bash Not tainted 6.12.0-rc4-g850925a8133c-dirty #49
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
RIP: 0010:umount_check+0xd0/0x100
Code: 8d 7c 24 40 e8 31 5a f4 ff 49 8b 54 24 40 41 56 49 89 e9 45 89 e8 48 89 d9 41 57 48 89 de 48 c7 c7 80 e7 db ac e8 f0 72 9a ff <0f> 0b 58 31 c0 5a 5b 5d 41 5c 41 5d 41 5e 41 5f e9 2b e5 5d 01 41
RSP: 0018:ffff88811cc27978 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff888140590ba0 RCX: ffffffffaaf20bae
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8881f6fb6f40
RBP: ffff8881462ec000 R08: 0000000000000001 R09: ffffed1023984ee3
R10: ffff88811cc2771f R11: 00000000016cfcc0 R12: ffff888134383e08
R13: 0000000000000002 R14: ffff8881462ec668 R15: ffffffffaceab4c0
FS:  00007f23bfa98740(0000) GS:ffff8881f6f80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556de4a6f808 CR3: 0000000123c80000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 d_walk+0x6a/0x530
 shrink_dcache_for_umount+0x6a/0x200
 generic_shutdown_super+0x52/0x2a0
 kill_anon_super+0x22/0x40
 cifs_kill_sb+0x159/0x1e0
 deactivate_locked_super+0x66/0xe0
 cleanup_mnt+0x140/0x210
 task_work_run+0xfb/0x170
 syscall_exit_to_user_mode+0x29f/0x2b0
 do_syscall_64+0xa1/0x1a0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f23bfb93ae7
Code: ff ff ff ff c3 66 0f 1f 44 00 00 48 8b 0d 11 93 0d 00 f7 d8 64 89 01 b8 ff ff ff ff eb bf 0f 1f 44 00 00 b8 50 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 92 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffee9138598 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: 0000000000000000 RBX: 0000558f1803e9a0 RCX: 00007f23bfb93ae7
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000558f1803e9a0
RBP: 0000558f1803e600 R08: 0000000000000007 R09: 0000558f17fab610
R10: d91d5ec34ab757b0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000015 R15: 0000000000000000
 </TASK>
irq event stamp: 1163486
hardirqs last  enabled at (1163485): [<ffffffffac98d344>] _raw_spin_unlock_irqrestore+0x34/0x60
hardirqs last disabled at (1163486): [<ffffffffac97dcfc>] __schedule+0xc7c/0x19a0
softirqs last  enabled at (1163482): [<ffffffffab79a3ee>] __smb_send_rqst+0x3de/0x990
softirqs last disabled at (1163480): [<ffffffffac2314f1>] release_sock+0x21/0xf0
---[ end trace 0000000000000000 ]---

VFS: Busy inodes after unmount of cifs (cifs)
------------[ cut here ]------------
kernel BUG at fs/super.c:661!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 3433 Comm: bash Tainted: G        W          6.12.0-rc4-g850925a8133c-dirty #49
Tainted: [W]=WARN
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
RIP: 0010:generic_shutdown_super+0x290/0x2a0
Code: e8 15 7c f7 ff 48 8b 5d 28 48 89 df e8 09 7c f7 ff 48 8b 0b 48 89 ee 48 8d 95 68 06 00 00 48 c7 c7 80 7f db ac e8 00 69 af ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90
RSP: 0018:ffff88811cc27a50 EFLAGS: 00010246
RAX: 000000000000003e RBX: ffffffffae994420 RCX: 0000000000000027
RDX: 0000000000000000 RSI: ffffffffab06180e RDI: ffff8881f6eb18c8
RBP: ffff8881462ec000 R08: 0000000000000001 R09: ffffed103edd6319
R10: ffff8881f6eb18cb R11: 00000000016d3158 R12: ffff8881462ec9c0
R13: ffff8881462ec050 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f23bfa98740(0000) GS:ffff8881f6e80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8364005d68 CR3: 0000000123c80000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 kill_anon_super+0x22/0x40
 cifs_kill_sb+0x159/0x1e0
 deactivate_locked_super+0x66/0xe0
 cleanup_mnt+0x140/0x210
 task_work_run+0xfb/0x170
 syscall_exit_to_user_mode+0x29f/0x2b0
 do_syscall_64+0xa1/0x1a0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f23bfb93ae7
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:generic_shutdown_super+0x290/0x2a0
Code: e8 15 7c f7 ff 48 8b 5d 28 48 89 df e8 09 7c f7 ff 48 8b 0b 48 89 ee 48 8d 95 68 06 00 00 48 c7 c7 80 7f db ac e8 00 69 af ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90
RSP: 0018:ffff88811cc27a50 EFLAGS: 00010246
RAX: 000000000000003e RBX: ffffffffae994420 RCX: 0000000000000027
RDX: 0000000000000000 RSI: ffffffffab06180e RDI: ffff8881f6eb18c8
RBP: ffff8881462ec000 R08: 0000000000000001 R09: ffffed103edd6319
R10: ffff8881f6eb18cb R11: 00000000016d3158 R12: ffff8881462ec9c0
R13: ffff8881462ec050 R14: 0000000000000001 R15: 0000000000000000
FS:  00007f23bfa98740(0000) GS:ffff8881f6e80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8364005d68 CR3: 0000000123c80000 CR4: 0000000000350ef0

This reproduces eventually with an SMB mount and two shells running
these loops concurrently

- while true; do
      cd ~; sleep 1;
      for i in {1..3}; do cd /mnt/test/subdir;
          echo $PWD; sleep 1; cd ..; echo $PWD; sleep 1;
      done;
      echo ...;
  done
- while true; do
      iptables -F OUTPUT; mount -t cifs -a;
      for _ in {0..2}; do ls /mnt/test/subdir/ | wc -l; done;
      iptables -I OUTPUT -p tcp --dport 445 -j DROP;
      sleep 10
      echo "unmounting"; umount -l -t cifs -a; echo "done unmounting";
      sleep 20
      echo "recovering"; iptables -F OUTPUT;
      sleep 10;
  done

Fixes: ebe98f1447 ("cifs: enable caching of directories for which a lease is held")
Fixes: 5c86919455 ("smb: client: fix use-after-free in smb2_query_info_compound()")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Aurich <paul@darkrain42.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-11-21 10:45:50 -06:00
arch - Make sure a kdump kernel with CONFIG_IMA_KEXEC enabled and booted on an AMD 2024-11-17 09:35:51 -08:00
block block-6.12-20241101 2024-11-01 13:41:55 -10:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes the following issues: 2024-10-16 08:42:54 -07:00
Documentation 10 hotfixes, 7 of which are cc:stable. All singletons, please see the 2024-11-16 16:00:38 -08:00
drivers drm/amdgpu regression fix for 6.12-rc8 2024-11-16 15:09:14 -08:00
fs smb: Don't leak cfid when reconnect races with open_cached_dir 2024-11-21 10:45:50 -06:00
include 10 hotfixes, 7 of which are cc:stable. All singletons, please see the 2024-11-16 16:00:38 -08:00
init cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS 2024-10-13 22:23:13 +02:00
io_uring io_uring/rw: fix missing NOWAIT check for O_DIRECT start write 2024-10-31 08:21:02 -06:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel 10 hotfixes, 7 of which are cc:stable. All singletons, please see the 2024-11-16 16:00:38 -08:00
lib objpool: fix to make percpu slot allocation more robust 2024-11-07 14:14:58 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm 10 hotfixes, 7 of which are cc:stable. All singletons, please see the 2024-11-16 16:00:38 -08:00
net Including fixes from bluetooth. 2024-11-14 10:05:33 -08:00
rust Driver core fix for 6.12-rc3 2024-10-13 09:10:52 -07:00
samples Including fixes from bluetooth. 2024-11-14 10:05:33 -08:00
scripts Kbuild fixes for v6.12 (2nd) 2024-11-03 08:29:02 -10:00
security integrity-v6.12 2024-11-12 13:06:31 -08:00
sound ASoC: Fixes for v6.12 2024-11-14 16:40:15 +01:00
tools 10 hotfixes, 7 of which are cc:stable. All singletons, please see the 2024-11-16 16:00:38 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt ARM64: 2024-10-21 11:22:04 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap mailmap: add entry for Thorsten Blum 2024-11-07 14:14:59 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS MAINTAINERS: Remove self from DSA entry 2024-11-03 12:52:38 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS Including fixes from bluetooth. 2024-11-14 10:05:33 -08:00
Makefile Linux 6.12 2024-11-17 14:15:08 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.