On 12/10/20 7:40 PM, Rob Clark wrote:

From: Rob Clark robdclark@chromium.org

[  192.062000] ------------[ cut here ]------------ [  192.062498] WARNING: CPU: 3 PID: 2039 at

drivers/gpu/drm/msm/msm_gem.c:381 put_iova_vmas+0x94/0xa0 [msm]

[  192.062870] Modules linked in: snd_hrtimer snd_seq snd_seq_device

rfcomm algif_hash algif_skcipher af_alg bnep xt_CHECKSUM nft_chain_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_counter xt_tcpudp nft_compat cpufreq_powersave cpufreq_conservative q6asm_dai q6routing q6afe_dai q6adm bridge q6afe q6asm q6dsp_common q6core stp llc nf_tables libcrc32c nfnetlink snd_soc_wsa881x regmap_sdw soundwire_qcom gpio_wcd934x snd_soc_wcd934x wcd934x regmap_slimbus venus_enc venus_dec apr videobuf2_dma_sg qrtr_smd uvcvideo videobuf2_vmalloc videobuf2_memops ath10k_snoc ath10k_core hci_uart btqca btbcm mac80211 bluetooth snd_soc_sdm845 ath snd_soc_rt5663 snd_soc_qcom_common snd_soc_rl6231 soundwire_bus ecdh_generic ecc qcom_spmi_adc5 venus_core qcom_pon qcom_spmi_temp_alarm qcom_vadc_common v4l2_mem2mem videobuf2_v4l2 cfg80211 videobuf2_common hid_multitouch reset_qcom_pdc qcrypto qcom_rng rfkill qcom_q6v5_mss libarc4 libdes qrtr ns qcom_wdt socinfo slim_qcom_ngd_ctrl

[  192.065739]  pdr_interface qcom_q6v5_pas slimbus qcom_pil_info

qcom_q6v5 qcom_sysmon qcom_common qcom_glink_smem qmi_helpers rmtfs_mem tcp_bbr sch_fq fuse ip_tables x_tables ipv6 crc_ccitt ti_sn65dsi86 i2c_hid msm mdt_loader llcc_qcom rtc_pm8xxx ocmem drm_kms_helper crct10dif_ce phy_qcom_qusb2 i2c_qcom_geni panel_simple drm pwm_bl

[  192.066066] CPU: 3 PID: 2039 Comm: gnome-shell Tainted: G

W         5.10.0-rc7-next-20201208 #1

[  192.066068] Hardware name: LENOVO 81JL/LNVNB161216, BIOS

9UCN33WW(V2.06) 06/ 4/2019

[  192.066072] pstate: 40400005 (nZcv daif +PAN -UAO -TCO BTYPE=--) [  192.066099] pc : put_iova_vmas+0x94/0xa0 [msm] [  192.066262] lr : put_iova_vmas+0x1c/0xa0 [msm] [  192.066403] sp : ffff800019efbbb0 [  192.066405] x29: ffff800019efbbb0 x28: ffff800019efbd88 [  192.066411] x27: 0000000000000000 x26: ffff109582efa400 [  192.066417] x25: 0000000000000009 x24: 000000000000012b [  192.066422] x23: ffff109582efa438 x22: ffff109582efa450 [  192.066427] x21: ffff109582efa528 x20: ffff1095cbd4f200 [  192.066432] x19: ffff1095cbd4f200 x18: 0000000000000000 [  192.066438] x17: 0000000000000000 x16: ffffc26c200ca750 [  192.066727] x15: 0000000000000000 x14: 0000000000000000 [  192.066741] x13: ffff1096fb8c9100 x12: 0000000000000002 [  192.066754] x11: ffffffffffffffff x10: 0000000000000002 [  192.067046] x9 : 0000000000000001 x8 : 0000000000000a36 [  192.067060] x7 : ffff4e2ad9f11000 x6 : ffffc26c216d4000 [  192.067212] x5 : ffffc26c2022661c x4 : ffff1095c2b98000 [  192.067367] x3 : ffff1095cbd4f300 x2 : 0000000000000000 [  192.067380] x1 : ffff1095c2b98000 x0 : 0000000000000000 [  192.067667] Call trace: [  192.067734]  put_iova_vmas+0x94/0xa0 [msm] [  192.068078]  msm_gem_free_object+0xb4/0x110 [msm] [  192.068399]  drm_gem_object_free+0x1c/0x30 [drm] [  192.068717]  drm_gem_object_handle_put_unlocked+0xf0/0xf8 [drm] [  192.069032]  drm_gem_object_release_handle+0x6c/0x88 [drm] [  192.069349]  drm_gem_handle_delete+0x68/0xc0 [drm] [  192.069666]  drm_gem_close_ioctl+0x30/0x48 [drm] [  192.069984]  drm_ioctl_kernel+0xc0/0x110 [drm] [  192.070303]  drm_ioctl+0x210/0x440 [drm] [  192.070588]  __arm64_sys_ioctl+0xa8/0xf0 [  192.070599]  el0_svc_common.constprop.0+0x74/0x190 [  192.070608]  do_el0_svc+0x24/0x90 [  192.070618]  el0_svc+0x14/0x20 [  192.070903]  el0_sync_handler+0xb0/0xb8 [  192.070911]  el0_sync+0x174/0x180 [  192.070918] ---[ end trace bee6b12a899001a3 ]--- [  192.072140] ------------[ cut here ]------------

Fixes: 9b73bde39cf2 ("drm/msm: Fix use-after-free in msm_gem with

carveout")

Signed-off-by: Rob Clark robdclark@chromium.org

drivers/gpu/drm/msm/msm_gem.c | 5 +++--   1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c

b/drivers/gpu/drm/msm/msm_gem.c

index 68a6c7eacc0a..a21be5b910ff 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -990,6 +990,8 @@ void msm_gem_free_object(struct drm_gem_object *obj)          if (msm_obj->pages)              kvfree(msm_obj->pages);

+        put_iova_vmas(obj);

/* dma_buf_detach() grabs resv lock, so we need to unlock           * prior to drm_prime_gem_destroy           */ @@ -999,11 +1001,10 @@ void msm_gem_free_object(struct drm_gem_object

*obj)

} else {          msm_gem_vunmap(obj);          put_pages(obj); +        put_iova_vmas(obj);          msm_gem_unlock(obj);      }

-    put_iova_vmas(obj);

drm_gem_object_release(obj);

kfree(msm_obj);

Ah, the put_iova_vmas needs to happen inside the msm_gem_lock|unlock. My bad!

Acked-by: Iskren Chernev iskren.chernev@gmail.com