From: Zheng Wang zyytlz.wz@163.com

mainline inclusion from mainline-v6.2-rc1 commit 643a16a0eb1d6ac23744bb6e90a00fc21148a9dc category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I5UBUF CVE: CVE-2022-3424

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id...

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In some bad situation, the gts may be freed gru_check_chiplet_assignment. The call chain can be gru_unload_context->gru_free_gru_context->gts_drop and kfree finally. However, the caller didn't know if the gts is freed or not and use it afterwards. This will trigger a Use after Free bug.

Fix it by introducing a return value to see if it's in error path or not. Free the gts in caller if gru_check_chiplet_assignment check failed.

Fixes: 55484c45dbec ("gru: allow users to specify gru chiplet 2") Signed-off-by: Zheng Wang zyytlz.wz@163.com Acked-by: Dimitri Sivanich sivanich@hpe.com Link: https://lore.kernel.org/r/20221110035033.19498-1-zyytlz.wz@163.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Yejian zhengyejian1@huawei.com Reviewed-by: Kuohai Xu xukuohai@huawei.com Reviewed-by: Xiu Jianfeng xiujianfeng@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- drivers/misc/sgi-gru/grufault.c | 13 +++++++++++-- drivers/misc/sgi-gru/grumain.c | 22 ++++++++++++++++++---- drivers/misc/sgi-gru/grutables.h | 2 +- 3 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c index 93be82fc338a..16df731e63c5 100644 --- a/drivers/misc/sgi-gru/grufault.c +++ b/drivers/misc/sgi-gru/grufault.c @@ -661,6 +661,7 @@ int gru_handle_user_call_os(unsigned long cb) if ((cb & (GRU_HANDLE_STRIDE - 1)) || ucbnum >= GRU_NUM_CB) return -EINVAL;

+again: gts = gru_find_lock_gts(cb); if (!gts) return -EINVAL; @@ -669,7 +670,11 @@ int gru_handle_user_call_os(unsigned long cb) if (ucbnum >= gts->ts_cbr_au_count * GRU_CBR_AU_SIZE) goto exit;

- gru_check_context_placement(gts); + if (gru_check_context_placement(gts)) { + gru_unlock_gts(gts); + gru_unload_context(gts, 1); + goto again; + }

/* * CCH may contain stale data if ts_force_cch_reload is set. @@ -887,7 +892,11 @@ int gru_set_context_option(unsigned long arg) } else { gts->ts_user_blade_id = req.val1; gts->ts_user_chiplet_id = req.val0; - gru_check_context_placement(gts); + if (gru_check_context_placement(gts)) { + gru_unlock_gts(gts); + gru_unload_context(gts, 1); + return ret; + } } break; case sco_gseg_owner: diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c index ab174f28e3be..8c3e0317c115 100644 --- a/drivers/misc/sgi-gru/grumain.c +++ b/drivers/misc/sgi-gru/grumain.c @@ -729,9 +729,10 @@ static int gru_check_chiplet_assignment(struct gru_state *gru, * chiplet. Misassignment can occur if the process migrates to a different * blade or if the user changes the selected blade/chiplet. */ -void gru_check_context_placement(struct gru_thread_state *gts) +int gru_check_context_placement(struct gru_thread_state *gts) { struct gru_state *gru; + int ret = 0;

/* * If the current task is the context owner, verify that the @@ -739,15 +740,23 @@ void gru_check_context_placement(struct gru_thread_state *gts) * references. Pthread apps use non-owner references to the CBRs. */ gru = gts->ts_gru; + /* + * If gru or gts->ts_tgid_owner isn't initialized properly, return + * success to indicate that the caller does not need to unload the + * gru context.The caller is responsible for their inspection and + * reinitialization if needed. + */ if (!gru || gts->ts_tgid_owner != current->tgid) - return; + return ret;

if (!gru_check_chiplet_assignment(gru, gts)) { STAT(check_context_unload); - gru_unload_context(gts, 1); + ret = -EINVAL; } else if (gru_retarget_intr(gts)) { STAT(check_context_retarget_intr); } + + return ret; }

@@ -947,7 +956,12 @@ vm_fault_t gru_fault(struct vm_fault *vmf) mutex_lock(&gts->ts_ctxlock); preempt_disable();

- gru_check_context_placement(gts); + if (gru_check_context_placement(gts)) { + preempt_enable(); + mutex_unlock(&gts->ts_ctxlock); + gru_unload_context(gts, 1); + return VM_FAULT_NOPAGE; + }

if (!gts->ts_gru) { STAT(load_user_context); diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h index 3e041b6f7a68..2becf4c3f7ca 100644 --- a/drivers/misc/sgi-gru/grutables.h +++ b/drivers/misc/sgi-gru/grutables.h @@ -652,7 +652,7 @@ extern int gru_user_flush_tlb(unsigned long arg); extern int gru_user_unload_context(unsigned long arg); extern int gru_get_exception_detail(unsigned long arg); extern int gru_set_context_option(unsigned long address); -extern void gru_check_context_placement(struct gru_thread_state *gts); +extern int gru_check_context_placement(struct gru_thread_state *gts); extern int gru_cpu_fault_map_id(void); extern struct vm_area_struct *gru_find_vma(unsigned long vaddr); extern void gru_flush_all_tlb(struct gru_state *gru);