leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
master
linux/security/selinux/ss
History
GONG, Ruiqi abe3c63144 selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 
The following warning was triggered on a hardware environment:

  SELinux: Converting 162 SID table entries...
  BUG: sleeping function called from invalid context at
       __might_sleep+0x60/0x74 0x0
  in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 5943, name: tar
  CPU: 7 PID: 5943 Comm: tar Tainted: P O 5.10.0 #1
  Call trace:
   dump_backtrace+0x0/0x1c8
   show_stack+0x18/0x28
   dump_stack+0xe8/0x15c
   ___might_sleep+0x168/0x17c
   __might_sleep+0x60/0x74
   __kmalloc_track_caller+0xa0/0x7dc
   kstrdup+0x54/0xac
   convert_context+0x48/0x2e4
   sidtab_context_to_sid+0x1c4/0x36c
   security_context_to_sid_core+0x168/0x238
   security_context_to_sid_default+0x14/0x24
   inode_doinit_use_xattr+0x164/0x1e4
   inode_doinit_with_dentry+0x1c0/0x488
   selinux_d_instantiate+0x20/0x34
   security_d_instantiate+0x70/0xbc
   d_splice_alias+0x4c/0x3c0
   ext4_lookup+0x1d8/0x200 [ext4]
   __lookup_slow+0x12c/0x1e4
   walk_component+0x100/0x200
   path_lookupat+0x88/0x118
   filename_lookup+0x98/0x130
   user_path_at_empty+0x48/0x60
   vfs_statx+0x84/0x140
   vfs_fstatat+0x20/0x30
   __se_sys_newfstatat+0x30/0x74
   __arm64_sys_newfstatat+0x1c/0x2c
   el0_svc_common.constprop.0+0x100/0x184
   do_el0_svc+0x1c/0x2c
   el0_svc+0x20/0x34
   el0_sync_handler+0x80/0x17c
   el0_sync+0x13c/0x140
  SELinux: Context system_u:object_r:pssp_rsyslog_log_t:s0:c0 is
           not valid (left unmapped).

It was found that within a critical section of spin_lock_irqsave in
sidtab_context_to_sid(), convert_context() (hooked by
sidtab_convert_params.func) might cause the process to sleep via
allocating memory with GFP_KERNEL, which is problematic.

As Ondrej pointed out [1], convert_context()/sidtab_convert_params.func
has another caller sidtab_convert_tree(), which is okay with GFP_KERNEL.
Therefore, fix this problem by adding a gfp_t argument for
convert_context()/sidtab_convert_params.func and pass GFP_KERNEL/_ATOMIC
properly in individual callers.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20221018120111.1474581-1-gongruiqi1@huawei.com/ [1]
Reported-by: Tan Ninghao <tanninghao1@huawei.com>
Fixes: ee1a84fdfe ("selinux: overhaul sidtab to fix bug and improve performance")
Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: wrap long BUG() output lines, tweak subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-10-19 09:55:53 -04:00
..
avtab.c selinux: declare data arrays const 2022-05-03 15:53:49 -04:00
avtab.h selinux: constify some avtab function arguments 2021-05-10 21:35:02 -04:00
conditional.c selinux/stable-5.18 PR 20220321 2022-03-21 20:47:54 -07:00
conditional.h selinux: refactor changing booleans 2020-08-17 21:00:33 -04:00
constraint.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
context.c selinux: hash context structure directly 2020-04-17 16:04:34 -04:00
context.h selinux: declare read-only parameters const 2022-08-30 17:14:36 -04:00
ebitmap.c selinux: declare read-only parameters const 2022-08-30 17:14:36 -04:00
ebitmap.h selinux: declare read-only parameters const 2022-08-30 17:14:36 -04:00
hashtab.c selinux: fix bad cleanup on error in hashtab_duplicate() 2022-05-17 18:34:35 -04:00
hashtab.h selinux: refactor changing booleans 2020-08-17 21:00:33 -04:00
mls_types.h selinux: declare read-only parameters const 2022-08-30 17:14:36 -04:00
mls.c selinux: drop return statement at end of void functions 2022-02-18 10:42:12 -05:00
mls.h selinux: hash context structure directly 2020-04-17 16:04:34 -04:00
policydb.c selinux: declare data arrays const 2022-05-03 15:53:49 -04:00
policydb.h selinux: Add boundary check in put_entry() 2022-06-14 21:52:37 -04:00
services.c selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-19 09:55:53 -04:00
services.h selinux: convert policy read-write lock to RCU 2020-08-25 08:34:47 -04:00
sidtab.c selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-19 09:55:53 -04:00
sidtab.h selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-19 09:55:53 -04:00
symtab.c selinux: prepare for inlining of hashtab functions 2020-07-09 19:05:36 -04:00
symtab.h selinux: specialize symtab insert and search functions 2020-07-08 20:21:43 -04:00