Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

apparmor: fix invalid deref of rawdata when export_binary is unset

If the export_binary parameter is disabled on runtime, profiles that were loaded before that will still have their rawdata stored in apparmorfs, with a symbolic link to the rawdata on the policy directory. When one of those profiles are replaced, the rawdata is set to NULL, but when trying to resolve the symbolic links to rawdata for that profile, it will try to dereference profile->rawdata->name when profile->rawdata is now NULL causing an oops. Fix it by checking if rawdata is set.

[ 168.653080] BUG: kernel NULL pointer dereference, address: 0000000000000088 [ 168.657420] #PF: supervisor read access in kernel mode [ 168.660619] #PF: error_code(0x0000) - not-present page [ 168.663613] PGD 0 P4D 0 [ 168.665450] Oops: Oops: 0000 [#1] SMP NOPTI [ 168.667836] CPU: 1 UID: 0 PID: 1729 Comm: ls Not tainted 6.19.0-rc7+ #3 PREEMPT(voluntary) [ 168.672308] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 168.679327] RIP: 0010:rawdata_get_link_base.isra.0+0x23/0x330 [ 168.682768] Code: 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 55 d0 48 85 ff 0f 84 e3 01 00 00 <48> 83 3c 25 88 00 00 00 00 0f 84 d4 01 00 00 49 89 f6 49 89 cc e8 [ 168.689818] RSP: 0018:ffffcdcb8200fb80 EFLAGS: 00010282 [ 168.690871] RAX: ffffffffaee74ec0 RBX: 000000000000000…