CVE-2025-39865

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

tee: fix NULL pointer dereference in tee_shm_put

tee_shm_put have NULL pointer dereference:

__optee_disable_shm_cache –> shm = reg_pair_to_ptr(…);//shm maybe return NULL tee_shm_free(shm); –> tee_shm_put(shm);//crash

Add check in tee_shm_put to fix it.

panic log: Unable to handle kernel paging request at virtual address 0000000000100cca Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=0000002049d07000 [0000000000100cca] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000096000004 [#1] SMP CPU: 2 PID: 14442 Comm: systemd-sleep Tainted: P OE ——- —- 6.6.0-39-generic #38 Source Version: 938b255f6cb8817c95b0dd5c8c2944acfce94b07 Hardware name: greatwall GW-001Y1A-FTH, BIOS Great Wall BIOS V3.0 10/26/2022 pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=–) pc : tee_shm_put+0x24/0x188 lr : tee_shm_free+0x14/0x28 sp : ffff001f98f9faf0 x29: ffff001f98f9faf0 x28: ffff0020df543cc0 x27: 0000000000000000 x26: ffff001f811344a0 x25: ffff8000818dac00 x24: ffff800082d8d048 x23: ffff001f850fcd18 x22: 0000000000000001 x21: ffff001f98f9fb88 x20: ffff001f83e76218 x19: ffff001f83e761e0 x18: 000000000000ffff x17: 303a30303a303030 x16: 0000000000000000 x15: 0000000000000003 x14: 0000000000000001 x13: 0000000000000000 x12: 0101010101010101 x11: 0000000000000001 x10: 0000000000000001 x9 : ffff800080e08d0c x8 : ffff001f98f9fb88 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : ffff001f83e761e0 x1 : 00000000ffff001f x0 : 0000000000100cca Call trace: tee_shm_put+0x24/0x188 tee_shm_free+0x14/0x28 __optee_disable_shm_cache+0xa8/0x108 optee_shutdown+0x28/0x38 platform_shutdown+0x28/0x40 device_shutdown+0x144/0x2b0 kernel_power_off+0x3c/0x80 hibernate+0x35c/0x388 state_store+0x64/0x80 kobj_attr_store+0x14/0x28 sysfs_kf_write+0x48/0x60 kernfs_fop_write_iter+0x128/0x1c0 vfs_write+0x270/0x370 ksys_write+0x6c/0x100 __arm64_sys_write+0x20/0x30 invoke_syscall+0x4c/0x120 el0_svc_common.constprop.0+0x44/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x24/0x88 el0t_64_sync_handler+0x134/0x150 el0t_64_sync+0x14c/0x15

Weakness

The product dereferences a pointer that it expects to be valid but is NULL.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/25e315bc8ad363bd1194e49062f183ad4011957e
• https://git.kernel.org/stable/c/4377eac565c297fdfccd2f8e9bf94ee84ff6172f
• https://git.kernel.org/stable/c/5e07a4235bb85d9ef664411e4ff4ac34783c18ff
• https://git.kernel.org/stable/c/963fca19fe34c496e04f7dd133b807b76a5434ca
• https://git.kernel.org/stable/c/add1ecc8f3ad8df22e3599c5c88d7907cc2a3079
• https://git.kernel.org/stable/c/e4a718a3a47e89805c3be9d46a84de1949a98d5d
• https://git.kernel.org/stable/c/f266188603c34e6e234fb0dfc3185f0ba98d71b7
• https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
• https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html