diff options
| author |   GONG, Ruiqi <gongruiqi1@huawei.com> | 2022-10-19 10:57:10 +0800 |
|---|---|---|
| committer |   Paul Moore <paul@paul-moore.com> | 2022-10-19 09:55:53 -0400 |
| commit | abe3c631447dcd1ba7af972fe6f054bee6f136fa (patch) | |
| tree | 18195112f8c26e0f9a61f02c90ffad90e4e613fd /security/selinux/ss/sidtab.c | |
| parent | Linux 6.1-rc1 (diff) | |
| download | linux-dev-abe3c631447dcd1ba7af972fe6f054bee6f136fa.tar.xz linux-dev-abe3c631447dcd1ba7af972fe6f054bee6f136fa.zip | |
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: ee1a84fdfeed ("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>
Diffstat (limited to 'security/selinux/ss/sidtab.c')
| -rw-r--r-- | security/selinux/ss/sidtab.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c index a54b8652bfb5..db5cce385bf8 100644 --- a/security/selinux/ss/sidtab.c +++ b/security/selinux/ss/sidtab.c @@ -325,7 +325,7 @@ int sidtab_context_to_sid(struct sidtab *s, struct context *context, } rc = convert->func(context, &dst_convert->context, - convert->args); + convert->args, GFP_ATOMIC); if (rc) { context_destroy(&dst->context); goto out_unlock; @@ -404,7 +404,7 @@ static int sidtab_convert_tree(union sidtab_entry_inner *edst, while (i < SIDTAB_LEAF_ENTRIES && *pos < count) { rc = convert->func(&esrc->ptr_leaf->entries[i].context, &edst->ptr_leaf->entries[i].context, - convert->args); + convert->args, GFP_KERNEL); if (rc) return rc; (*pos)++; |