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[PATCH OLK-5.10] drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap
by Zeng Heng 15 Jul '24

15 Jul '24

From: Anand K Mistry <amistry(a)google.com> mainline inclusion from mainline-v5.16-rc1 commit 8244a3bc27b3efd057da154b8d7e414670d5044f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9FNEV CVE: CVE-2021-47200 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… ---------------------------------- drm_gem_ttm_mmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that drop will free the gem object, and the subsequent drm_gem_object_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper. This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drm_gem_object_get() call in drm_gem_ttm_mmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero." Signed-off-by: Anand K Mistry <amistry(a)google.com> Fixes: 9786b65bc61a ("drm/ttm: fix mmap refcounting") Cc: Gerd Hoffmann <kraxel(a)redhat.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v5.5+ Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210930085932.1.I8043d61cc23… Conflicts: drivers/gpu/drm/drm_prime.c [Resolve conflicts due to several refactor patches not merged.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/gpu/drm/drm_prime.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 825499ea3ff5..893421d81e1e 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -724,11 +724,13 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); if (obj->funcs && obj->funcs->mmap) { + drm_gem_object_get(obj); ret = obj->funcs->mmap(obj, vma); - if (ret) + if (ret) { + drm_gem_object_put(obj); return ret; + } vma->vm_private_data = obj; - drm_gem_object_get(obj); return 0; } -- 2.25.1

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[PATCH openEuler-22.03-LTS-SP1] drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap
by Zeng Heng 15 Jul '24

15 Jul '24

From: Anand K Mistry <amistry(a)google.com> mainline inclusion from mainline-v5.16-rc1 commit 8244a3bc27b3efd057da154b8d7e414670d5044f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9FNEV CVE: CVE-2021-47200 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… ---------------------------------- drm_gem_ttm_mmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that drop will free the gem object, and the subsequent drm_gem_object_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper. This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drm_gem_object_get() call in drm_gem_ttm_mmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero." Signed-off-by: Anand K Mistry <amistry(a)google.com> Fixes: 9786b65bc61a ("drm/ttm: fix mmap refcounting") Cc: Gerd Hoffmann <kraxel(a)redhat.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v5.5+ Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210930085932.1.I8043d61cc23… Conflicts: drivers/gpu/drm/drm_prime.c [Resolve conflicts due to several refactor patches not merged.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/gpu/drm/drm_prime.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 825499ea3ff5..893421d81e1e 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -724,11 +724,13 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); if (obj->funcs && obj->funcs->mmap) { + drm_gem_object_get(obj); ret = obj->funcs->mmap(obj, vma); - if (ret) + if (ret) { + drm_gem_object_put(obj); return ret; + } vma->vm_private_data = obj; - drm_gem_object_get(obj); return 0; } -- 2.25.1

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[PATCH openEuler-22.03-LTS-SP1] drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap
by Zeng Heng 15 Jul '24

15 Jul '24

From: Anand K Mistry <amistry(a)google.com> mainline inclusion from mainline-v5.16-rc1 commit 8244a3bc27b3efd057da154b8d7e414670d5044f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9FNEV CVE: CVE-2021-47200 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… ---------------------------------- drm_gem_ttm_mmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that drop will free the gem object, and the subsequent drm_gem_object_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper. This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drm_gem_object_get() call in drm_gem_ttm_mmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero." Signed-off-by: Anand K Mistry <amistry(a)google.com> Fixes: 9786b65bc61a ("drm/ttm: fix mmap refcounting") Cc: Gerd Hoffmann <kraxel(a)redhat.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v5.5+ Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210930085932.1.I8043d61cc23… Conflicts: drivers/gpu/drm/drm_prime.c [Resolve conflicts due to several refactor patches not merged.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/gpu/drm/drm_prime.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 825499ea3ff5..c806cf4c9a48 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -724,11 +724,14 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); if (obj->funcs && obj->funcs->mmap) { + + drm_gem_object_get(obj); ret = obj->funcs->mmap(obj, vma); - if (ret) + if (ret) { + drm_gem_object_put(obj); return ret; + } vma->vm_private_data = obj; - drm_gem_object_get(obj); return 0; } -- 2.25.1

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[PATCH OLK-5.10] drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap
by Zeng Heng 15 Jul '24

15 Jul '24

From: Anand K Mistry <amistry(a)google.com> mainline inclusion from mainline-v5.16-rc1 commit 8244a3bc27b3efd057da154b8d7e414670d5044f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9FNEV CVE: CVE-2021-47200 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… ---------------------------------- drm_gem_ttm_mmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that drop will free the gem object, and the subsequent drm_gem_object_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper. This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drm_gem_object_get() call in drm_gem_ttm_mmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero." Signed-off-by: Anand K Mistry <amistry(a)google.com> Fixes: 9786b65bc61a ("drm/ttm: fix mmap refcounting") Cc: Gerd Hoffmann <kraxel(a)redhat.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v5.5+ Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210930085932.1.I8043d61cc23… Conflicts: drivers/gpu/drm/drm_prime.c [Resolve conflicts due to several refactor patches not merged.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/gpu/drm/drm_prime.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 825499ea3ff5..c806cf4c9a48 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -724,11 +724,14 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); if (obj->funcs && obj->funcs->mmap) { + + drm_gem_object_get(obj); ret = obj->funcs->mmap(obj, vma); - if (ret) + if (ret) { + drm_gem_object_put(obj); return ret; + } vma->vm_private_data = obj; - drm_gem_object_get(obj); return 0; } -- 2.25.1

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[PATCH OLK-5.10] drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap
by Zeng Heng 15 Jul '24

15 Jul '24

From: Anand K Mistry <amistry(a)google.com> mainline inclusion from mainline-v5.16-rc1 commit 8244a3bc27b3efd057da154b8d7e414670d5044f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9FNEV CVE: CVE-2021-47200 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… ---------------------------------- drm_gem_ttm_mmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that drop will free the gem object, and the subsequent drm_gem_object_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper. This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drm_gem_object_get() call in drm_gem_ttm_mmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero." Signed-off-by: Anand K Mistry <amistry(a)google.com> Fixes: 9786b65bc61a ("drm/ttm: fix mmap refcounting") Cc: Gerd Hoffmann <kraxel(a)redhat.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v5.5+ Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210930085932.1.I8043d61cc23… Conflicts: drivers/gpu/drm/drm_prime.c [Resolve conflicts due to several refactor patches not merged.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/gpu/drm/drm_prime.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 825499ea3ff5..c806cf4c9a48 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -724,11 +724,14 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); if (obj->funcs && obj->funcs->mmap) { + + drm_gem_object_get(obj); ret = obj->funcs->mmap(obj, vma); - if (ret) + if (ret) { + drm_gem_object_put(obj); return ret; + } vma->vm_private_data = obj; - drm_gem_object_get(obj); return 0; } -- 2.25.1

2 1

[PATCH openEuler-22.03-LTS-SP1] drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap
by Zeng Heng 15 Jul '24

15 Jul '24

From: Anand K Mistry <amistry(a)google.com> mainline inclusion from mainline-v5.16-rc1 commit 8244a3bc27b3efd057da154b8d7e414670d5044f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9FNEV CVE: CVE-2021-47200 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… ---------------------------------- drm_gem_ttm_mmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that drop will free the gem object, and the subsequent drm_gem_object_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper. This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drm_gem_object_get() call in drm_gem_ttm_mmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero." Signed-off-by: Anand K Mistry <amistry(a)google.com> Fixes: 9786b65bc61a ("drm/ttm: fix mmap refcounting") Cc: Gerd Hoffmann <kraxel(a)redhat.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Maxime Ripard <mripard(a)kernel.org> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: David Airlie <airlied(a)linux.ie> Cc: Daniel Vetter <daniel(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v5.5+ Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210930085932.1.I8043d61cc23… Conflicts: drivers/gpu/drm/drm_prime.c [Resolve conflicts due to several refactor patches not merged.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/gpu/drm/drm_prime.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 825499ea3ff5..c806cf4c9a48 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -724,11 +724,14 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); if (obj->funcs && obj->funcs->mmap) { + + drm_gem_object_get(obj); ret = obj->funcs->mmap(obj, vma); - if (ret) + if (ret) { + drm_gem_object_put(obj); return ret; + } vma->vm_private_data = obj; - drm_gem_object_get(obj); return 0; } -- 2.25.1

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[PATCH openEuler-22.03-LTS-SP1] powerpc/pseries: Enforce hcall result buffer validity and size
by Huang Xiaojia 15 Jul '24

15 Jul '24

From: Nathan Lynch <nathanl(a)linux.ibm.com> stable inclusion from stable-v4.19.317 commit acf2b80c31c37acab040baa3cf5f19fbd5140b18 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IACRHB CVE: CVE-2024-40974 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit ff2e185cf73df480ec69675936c4ee75a445c3e4 ] plpar_hcall(), plpar_hcall9(), and related functions expect callers to provide valid result buffers of certain minimum size. Currently this is communicated only through comments in the code and the compiler has no idea. For example, if I write a bug like this: long retbuf[PLPAR_HCALL_BUFSIZE]; // should be PLPAR_HCALL9_BUFSIZE plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, ...); This compiles with no diagnostics emitted, but likely results in stack corruption at runtime when plpar_hcall9() stores results past the end of the array. (To be clear this is a contrived example and I have not found a real instance yet.) To make this class of error less likely, we can use explicitly-sized array parameters instead of pointers in the declarations for the hcall APIs. When compiled with -Warray-bounds[1], the code above now provokes a diagnostic like this: error: array argument is too small; is of size 32, callee requires at least 72 [-Werror,-Warray-bounds] 60 | plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, | ^ ~~~~~~ [1] Enabled for LLVM builds but not GCC for now. See commit 0da6e5fd6c37 ("gcc: disable '-Warray-bounds' for gcc-13 too") and related changes. Signed-off-by: Nathan Lynch <nathanl(a)linux.ibm.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Link: https://msgid.link/20240408-pseries-hvcall-retbuf-v1-1-ebc73d7253cf@linux.i… Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Huang Xiaojia <huangxiaojia2(a)huawei.com> --- arch/powerpc/include/asm/hvcall.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index 00c8cda1c9c3..a8035af4fc50 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -453,7 +453,7 @@ long plpar_hcall_norets_notrace(unsigned long opcode, ...); * Used for all but the craziest of phyp interfaces (see plpar_hcall9) */ #define PLPAR_HCALL_BUFSIZE 4 -long plpar_hcall(unsigned long opcode, unsigned long *retbuf, ...); +long plpar_hcall(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL_BUFSIZE], ...); /** * plpar_hcall_raw: - Make a hypervisor call without calculating hcall stats @@ -467,7 +467,7 @@ long plpar_hcall(unsigned long opcode, unsigned long *retbuf, ...); * plpar_hcall, but plpar_hcall_raw works in real mode and does not * calculate hypervisor call statistics. */ -long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...); +long plpar_hcall_raw(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL_BUFSIZE], ...); /** * plpar_hcall9: - Make a pseries hypervisor call with up to 9 return arguments @@ -478,8 +478,8 @@ long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...); * PLPAR_HCALL9_BUFSIZE to size the return argument buffer. */ #define PLPAR_HCALL9_BUFSIZE 9 -long plpar_hcall9(unsigned long opcode, unsigned long *retbuf, ...); -long plpar_hcall9_raw(unsigned long opcode, unsigned long *retbuf, ...); +long plpar_hcall9(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL9_BUFSIZE], ...); +long plpar_hcall9_raw(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL9_BUFSIZE], ...); struct hvcall_mpp_data { unsigned long entitled_mem; -- 2.34.1

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[PATCH openEuler-1.0-LTS] powerpc/pseries: Enforce hcall result buffer validity and size
by Huang Xiaojia 15 Jul '24

15 Jul '24

From: Nathan Lynch <nathanl(a)linux.ibm.com> stable inclusion from stable-v4.19.317 commit acf2b80c31c37acab040baa3cf5f19fbd5140b18 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IACRHB CVE: CVE-2024-40974 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit ff2e185cf73df480ec69675936c4ee75a445c3e4 ] plpar_hcall(), plpar_hcall9(), and related functions expect callers to provide valid result buffers of certain minimum size. Currently this is communicated only through comments in the code and the compiler has no idea. For example, if I write a bug like this: long retbuf[PLPAR_HCALL_BUFSIZE]; // should be PLPAR_HCALL9_BUFSIZE plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, ...); This compiles with no diagnostics emitted, but likely results in stack corruption at runtime when plpar_hcall9() stores results past the end of the array. (To be clear this is a contrived example and I have not found a real instance yet.) To make this class of error less likely, we can use explicitly-sized array parameters instead of pointers in the declarations for the hcall APIs. When compiled with -Warray-bounds[1], the code above now provokes a diagnostic like this: error: array argument is too small; is of size 32, callee requires at least 72 [-Werror,-Warray-bounds] 60 | plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, | ^ ~~~~~~ [1] Enabled for LLVM builds but not GCC for now. See commit 0da6e5fd6c37 ("gcc: disable '-Warray-bounds' for gcc-13 too") and related changes. Signed-off-by: Nathan Lynch <nathanl(a)linux.ibm.com> Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au> Link: https://msgid.link/20240408-pseries-hvcall-retbuf-v1-1-ebc73d7253cf@linux.i… Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Huang Xiaojia <huangxiaojia2(a)huawei.com> --- arch/powerpc/include/asm/hvcall.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index a0b17f9f1ea4..8347f57e1c6a 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -383,7 +383,7 @@ long plpar_hcall_norets(unsigned long opcode, ...); * Used for all but the craziest of phyp interfaces (see plpar_hcall9) */ #define PLPAR_HCALL_BUFSIZE 4 -long plpar_hcall(unsigned long opcode, unsigned long *retbuf, ...); +long plpar_hcall(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL_BUFSIZE], ...); /** * plpar_hcall_raw: - Make a hypervisor call without calculating hcall stats @@ -397,7 +397,7 @@ long plpar_hcall(unsigned long opcode, unsigned long *retbuf, ...); * plpar_hcall, but plpar_hcall_raw works in real mode and does not * calculate hypervisor call statistics. */ -long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...); +long plpar_hcall_raw(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL_BUFSIZE], ...); /** * plpar_hcall9: - Make a pseries hypervisor call with up to 9 return arguments @@ -408,8 +408,8 @@ long plpar_hcall_raw(unsigned long opcode, unsigned long *retbuf, ...); * PLPAR_HCALL9_BUFSIZE to size the return argument buffer. */ #define PLPAR_HCALL9_BUFSIZE 9 -long plpar_hcall9(unsigned long opcode, unsigned long *retbuf, ...); -long plpar_hcall9_raw(unsigned long opcode, unsigned long *retbuf, ...); +long plpar_hcall9(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL9_BUFSIZE], ...); +long plpar_hcall9_raw(unsigned long opcode, unsigned long retbuf[static PLPAR_HCALL9_BUFSIZE], ...); struct hvcall_mpp_data { unsigned long entitled_mem; -- 2.34.1

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[PATCH openEuler-22.03-LTS-SP1 0/1] powerpc/pseries: Enforce hcall result buffer validity and size
by Huang Xiaojia 15 Jul '24

15 Jul '24

*** BLURB HERE *** Nathan Lynch (1): powerpc/pseries: Enforce hcall result buffer validity and size arch/powerpc/include/asm/hvcall.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) -- 2.34.1

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[PATCH OLK-6.6 0/1] powerpc/pseries: Enforce hcall result buffer validity and size
by Huang Xiaojia 15 Jul '24

15 Jul '24

*** BLURB HERE *** Nathan Lynch (1): powerpc/pseries: Enforce hcall result buffer validity and size arch/powerpc/include/asm/hvcall.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) -- 2.34.1

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