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author | Sachin Grover <sgrover@codeaurora.org> | 2018-05-25 11:31:39 +0300 |
---|---|---|
committer | Paul Moore <paul@paul-moore.com> | 2018-05-30 03:11:19 +0300 |
commit | efe3de79e0b52ca281ef6691480c8c68c82a4657 (patch) | |
tree | d5e01db9e337bc206053cd19cce624c34814e86c | |
parent | 4152dc91b5932e7fe49a5afed62a068b2f31d196 (diff) | |
download | linux-efe3de79e0b52ca281ef6691480c8c68c82a4657.tar.xz |
selinux: KASAN: slab-out-of-bounds in xattr_getsecurity
Call trace:
[<ffffff9203a8d7a8>] dump_backtrace+0x0/0x428
[<ffffff9203a8dbf8>] show_stack+0x28/0x38
[<ffffff920409bfb8>] dump_stack+0xd4/0x124
[<ffffff9203d187e8>] print_address_description+0x68/0x258
[<ffffff9203d18c00>] kasan_report.part.2+0x228/0x2f0
[<ffffff9203d1927c>] kasan_report+0x5c/0x70
[<ffffff9203d1776c>] check_memory_region+0x12c/0x1c0
[<ffffff9203d17cdc>] memcpy+0x34/0x68
[<ffffff9203d75348>] xattr_getsecurity+0xe0/0x160
[<ffffff9203d75490>] vfs_getxattr+0xc8/0x120
[<ffffff9203d75d68>] getxattr+0x100/0x2c8
[<ffffff9203d76fb4>] SyS_fgetxattr+0x64/0xa0
[<ffffff9203a83f70>] el0_svc_naked+0x24/0x28
If user get root access and calls security.selinux setxattr() with an
embedded NUL on a file and then if some process performs a getxattr()
on that file with a length greater than the actual length of the string,
it would result in a panic.
To fix this, add the actual length of the string to the security context
instead of the length passed by the userspace process.
Signed-off-by: Sachin Grover <sgrover@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <paul@paul-moore.com>
-rw-r--r-- | security/selinux/ss/services.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 8057e19dc15f..3ce225e3f142 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1494,7 +1494,7 @@ static int security_context_to_sid_core(struct selinux_state *state, scontext_len, &context, def_sid); if (rc == -EINVAL && force) { context.str = str; - context.len = scontext_len; + context.len = strlen(str) + 1; str = NULL; } else if (rc) goto out_unlock; |