linux-dev/fs/cifs, branch master

cifs: fix use-after-free on the link name

2022-11-05T04:36:54Z

xfstests generic/011 reported use-after-free bug as follows: BUG: KASAN: use-after-free in __d_alloc+0x269/0x859 Read of size 15 at addr ffff8880078933a0 by task dirstress/952 CPU: 1 PID: 952 Comm: dirstress Not tainted 6.1.0-rc3+ #77 Call Trace: __dump_stack+0x23/0x29 dump_stack_lvl+0x51/0x73 print_address_description+0x67/0x27f print_report+0x3e/0x5c kasan_report+0x7b/0xa8 kasan_check_range+0x1b2/0x1c1 memcpy+0x22/0x5d __d_alloc+0x269/0x859 d_alloc+0x45/0x20c d_alloc_parallel+0xb2/0x8b2 lookup_open+0x3b8/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd Allocated by task 952: kasan_save_stack+0x1f/0x42 kasan_set_track+0x21/0x2a kasan_save_alloc_info+0x17/0x1d __kasan_kmalloc+0x7e/0x87 __kmalloc_node_track_caller+0x59/0x155 kstrndup+0x60/0xe6 parse_mf_symlink+0x215/0x30b check_mf_symlink+0x260/0x36a cifs_get_inode_info+0x14e1/0x1690 cifs_revalidate_dentry_attr+0x70d/0x964 cifs_revalidate_dentry+0x36/0x62 cifs_d_revalidate+0x162/0x446 lookup_open+0x36f/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 950: kasan_save_stack+0x1f/0x42 kasan_set_track+0x21/0x2a kasan_save_free_info+0x1c/0x34 ____kasan_slab_free+0x1c1/0x1d5 __kasan_slab_free+0xe/0x13 __kmem_cache_free+0x29a/0x387 kfree+0xd3/0x10e cifs_fattr_to_inode+0xb6a/0xc8c cifs_get_inode_info+0x3cb/0x1690 cifs_revalidate_dentry_attr+0x70d/0x964 cifs_revalidate_dentry+0x36/0x62 cifs_d_revalidate+0x162/0x446 lookup_open+0x36f/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd When opened a symlink, link name is from 'inode->i_link', but it may be reset to a new value when revalidate the dentry. If some processes get the link name on the race scenario, then UAF will happen on link name. Fix this by implementing 'get_link' interface to duplicate the link name. Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+") Signed-off-by: ChenXiaoSong Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: avoid unnecessary iteration of tcp sessions

2022-11-05T04:34:40Z

In a few places, we do unnecessary iterations of tcp sessions, even when the server struct is provided. The change avoids it and uses the server struct provided. Signed-off-by: Shyam Prasad N Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: always iterate smb sessions using primary channel

2022-11-05T04:34:02Z

smb sessions and tcons currently hang off primary channel only. Secondary channels have the lists as empty. Whenever there's a need to iterate sessions or tcons, we should use the list in the corresponding primary channel. Signed-off-by: Shyam Prasad N Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: fix use-after-free caused by invalid pointer `hostname`

2022-10-28T04:59:13Z

`hostname` needs to be set as null-pointer after free in `cifs_put_tcp_session` function, or when `cifsd` thread attempts to resolve hostname and reconnect the host, the thread would deref the invalid pointer. Here is one of practical backtrace examples as reference: Task 477 --------------------------- do_mount path_mount do_new_mount vfs_get_tree smb3_get_tree smb3_get_tree_common cifs_smb3_do_mount cifs_mount mount_put_conns cifs_put_tcp_session --> kfree(server->hostname) cifsd --------------------------- kthread cifs_demultiplex_thread cifs_reconnect reconn_set_ipaddr_from_hostname --> if (!server->hostname) --> if (server->hostname[0] == '\0') // !! UAF fault here CIFS: VFS: cifs_mount failed w/return code = -112 mount error(112): Host is down BUG: KASAN: use-after-free in reconn_set_ipaddr_from_hostname+0x2ba/0x310 Read of size 1 at addr ffff888108f35380 by task cifsd/480 CPU: 2 PID: 480 Comm: cifsd Not tainted 6.1.0-rc2-00106-gf705792f89dd-dirty #25 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: dump_stack_lvl+0x68/0x85 print_report+0x16c/0x4a3 kasan_report+0x95/0x190 reconn_set_ipaddr_from_hostname+0x2ba/0x310 __cifs_reconnect.part.0+0x241/0x800 cifs_reconnect+0x65f/0xb60 cifs_demultiplex_thread+0x1570/0x2570 kthread+0x2c5/0x380 ret_from_fork+0x22/0x30 Allocated by task 477: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x7e/0x90 __kmalloc_node_track_caller+0x52/0x1b0 kstrdup+0x3b/0x70 cifs_get_tcp_session+0xbc/0x19b0 mount_get_conns+0xa9/0x10c0 cifs_mount+0xdf/0x1970 cifs_smb3_do_mount+0x295/0x1660 smb3_get_tree+0x352/0x5e0 vfs_get_tree+0x8e/0x2e0 path_mount+0xf8c/0x1990 do_mount+0xee/0x110 __x64_sys_mount+0x14b/0x1f0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 477: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x50 __kasan_slab_free+0x10a/0x190 __kmem_cache_free+0xca/0x3f0 cifs_put_tcp_session+0x30c/0x450 cifs_mount+0xf95/0x1970 cifs_smb3_do_mount+0x295/0x1660 smb3_get_tree+0x352/0x5e0 vfs_get_tree+0x8e/0x2e0 path_mount+0xf8c/0x1990 do_mount+0xee/0x110 __x64_sys_mount+0x14b/0x1f0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888108f35380 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of 16-byte region [ffff888108f35380, ffff888108f35390) The buggy address belongs to the physical page: page:00000000333f8e58 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888108f350e0 pfn:0x108f35 flags: 0x200000000000200(slab|node=0|zone=2) raw: 0200000000000200 0000000000000000 dead000000000122 ffff8881000423c0 raw: ffff888108f350e0 000000008080007a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888108f35280: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc ffff888108f35300: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc >ffff888108f35380: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc ^ ffff888108f35400: fa fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888108f35480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc Fixes: 7be3248f3139 ("cifs: To match file servers, make sure the server hostname matches") Signed-off-by: Zeng Heng Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: Fix pages leak when writedata alloc failed in cifs_write_from_iter()

2022-10-23T22:50:10Z

There is a kmemleak when writedata alloc failed: unreferenced object 0xffff888175ae4000 (size 4096): comm "dd", pid 19419, jiffies 4296028749 (age 739.396s) hex dump (first 32 bytes): 80 02 b0 04 00 ea ff ff c0 02 b0 04 00 ea ff ff ................ 80 22 4c 04 00 ea ff ff c0 22 4c 04 00 ea ff ff ."L......"L..... backtrace: [<0000000072fdbb86>] __kmalloc_node+0x50/0x150 [<0000000039faf56f>] __iov_iter_get_pages_alloc+0x605/0xdd0 [<00000000f862a9d4>] iov_iter_get_pages_alloc2+0x3b/0x80 [<000000008f226067>] cifs_write_from_iter+0x2ae/0xe40 [<000000001f78f2f1>] __cifs_writev+0x337/0x5c0 [<00000000257fcef5>] vfs_write+0x503/0x690 [<000000008778a238>] ksys_write+0xb9/0x150 [<00000000ed82047c>] do_syscall_64+0x35/0x80 [<000000003365551d>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 __iov_iter_get_pages_alloc+0x605/0xdd0 is: want_pages_array at lib/iov_iter.c:1304 (inlined by) __iov_iter_get_pages_alloc at lib/iov_iter.c:1457 If writedata allocate failed, the pages and pagevec should be cleanup. Fixes: 8c5f9c1ab7cb ("CIFS: Add support for direct I/O write") Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Zhang Xiaoxu Signed-off-by: Steve French

cifs: Fix pages array leak when writedata alloc failed in cifs_writedata_alloc()

2022-10-23T22:50:10Z

There is a memory leak when writedata alloc failed: unreferenced object 0xffff888192364000 (size 8192): comm "sync", pid 22839, jiffies 4297313967 (age 60.230s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000027de0814>] __kmalloc+0x4d/0x150 [<00000000b21e81ab>] cifs_writepages+0x35f/0x14a0 [<0000000076f7d20e>] do_writepages+0x10a/0x360 [<00000000d6a36edc>] filemap_fdatawrite_wbc+0x95/0xc0 [<000000005751a323>] __filemap_fdatawrite_range+0xa7/0xe0 [<0000000088afb0ca>] file_write_and_wait_range+0x66/0xb0 [<0000000063dbc443>] cifs_strict_fsync+0x80/0x5f0 [<00000000c4624754>] __x64_sys_fsync+0x40/0x70 [<000000002c0dc744>] do_syscall_64+0x35/0x80 [<0000000052f46bee>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 cifs_writepages+0x35f/0x14a0 is: kmalloc_array at include/linux/slab.h:628 (inlined by) kcalloc at include/linux/slab.h:659 (inlined by) cifs_writedata_alloc at fs/cifs/file.c:2438 (inlined by) wdata_alloc_and_fillpages at fs/cifs/file.c:2527 (inlined by) cifs_writepages at fs/cifs/file.c:2705 If writedata alloc failed in cifs_writedata_alloc(), the pages array should be freed. Fixes: 8e7360f67e75 ("CIFS: Add support for direct pages in wdata") Signed-off-by: Zhang Xiaoxu Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: update internal module number

2022-10-19T22:57:51Z

To 2.40 Signed-off-by: Steve French

cifs: fix memory leaks in session setup

2022-10-19T22:57:51Z

We were only zeroing out the ntlmssp blob but forgot to free the allocated buffer in the end of SMB2_sess_auth_rawntlmssp_negotiate() and SMB2_sess_auth_rawntlmssp_authenticate() functions. This fixes below kmemleak reports: unreferenced object 0xffff88800ddcfc60 (size 96): comm "mount.cifs", pid 758, jiffies 4294696066 (age 42.967s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d0beeb29>] __kmalloc+0x39/0xa0 [<00000000e3834047>] build_ntlmssp_smb3_negotiate_blob+0x2c/0x110 [cifs] [<00000000e85f5ab2>] SMB2_sess_auth_rawntlmssp_negotiate+0xd3/0x230 [cifs] [<0000000080fdb897>] SMB2_sess_setup+0x16c/0x2a0 [cifs] [<000000009af320a8>] cifs_setup_session+0x13b/0x370 [cifs] [<00000000f15d5982>] cifs_get_smb_ses+0x643/0xb90 [cifs] [<00000000fe15eb90>] mount_get_conns+0x63/0x3e0 [cifs] [<00000000768aba03>] mount_get_dfs_conns+0x16/0xa0 [cifs] [<00000000cf1cf146>] cifs_mount+0x1c2/0x9a0 [cifs] [<000000000d66b51e>] cifs_smb3_do_mount+0x10e/0x710 [cifs] [<0000000077a996c5>] smb3_get_tree+0xf4/0x200 [cifs] [<0000000094dbd041>] vfs_get_tree+0x23/0xc0 [<000000003a8561de>] path_mount+0x2d3/0xb50 [<00000000ed5c86d6>] __x64_sys_mount+0x102/0x140 [<00000000142142f3>] do_syscall_64+0x3b/0x90 [<00000000e2b89731>] entry_SYSCALL_64_after_hwframe+0x63/0xcd unreferenced object 0xffff88801437f000 (size 512): comm "mount.cifs", pid 758, jiffies 4294696067 (age 42.970s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d0beeb29>] __kmalloc+0x39/0xa0 [<00000000004f53d2>] build_ntlmssp_auth_blob+0x4f/0x340 [cifs] [<000000005f333084>] SMB2_sess_auth_rawntlmssp_authenticate+0xd4/0x250 [cifs] [<0000000080fdb897>] SMB2_sess_setup+0x16c/0x2a0 [cifs] [<000000009af320a8>] cifs_setup_session+0x13b/0x370 [cifs] [<00000000f15d5982>] cifs_get_smb_ses+0x643/0xb90 [cifs] [<00000000fe15eb90>] mount_get_conns+0x63/0x3e0 [cifs] [<00000000768aba03>] mount_get_dfs_conns+0x16/0xa0 [cifs] [<00000000cf1cf146>] cifs_mount+0x1c2/0x9a0 [cifs] [<000000000d66b51e>] cifs_smb3_do_mount+0x10e/0x710 [cifs] [<0000000077a996c5>] smb3_get_tree+0xf4/0x200 [cifs] [<0000000094dbd041>] vfs_get_tree+0x23/0xc0 [<000000003a8561de>] path_mount+0x2d3/0xb50 [<00000000ed5c86d6>] __x64_sys_mount+0x102/0x140 [<00000000142142f3>] do_syscall_64+0x3b/0x90 [<00000000e2b89731>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: a4e430c8c8ba ("cifs: replace kfree() with kfree_sensitive() for sensitive data") Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: drop the lease for cached directories on rmdir or rename

2022-10-19T22:57:41Z

When we delete or rename a directory we must also drop any cached lease we have on the directory. Fixes: a350d6e73f5e ("cifs: enable caching of directories for which a lease is held") Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French

smb3: interface count displayed incorrectly

2022-10-19T15:06:23Z

The "Server interfaces" count in /proc/fs/cifs/DebugData increases as the interfaces are requeried, rather than being reset to the new value. This could cause a problem if the server disabled multichannel as the iface_count is checked in try_adding_channels to see if multichannel still supported. Also fixes a coverity warning: Addresses-Coverity: 1526374 ("Concurrent data access violations (MISSING_LOCK)") Cc: Reviewed-by: Bharath SM Reviewed-by: Shyam Prasad N Signed-off-by: Steve French