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[PATCH OLK-5.10] drm/amd/display: Fix index out of bounds in degamma hardware format translation
by Liu Chuang 29 Oct '24

29 Oct '24

From: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> stable inclusion from stable-v5.10.227 commit c130a3c09e3746c1a09ce26c20d21d449d039b1d category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYR9A CVE: CVE-2024-49894 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit b7e99058eb2e86aabd7a10761e76cae33d22b49f ] Fixes index out of bounds issue in `cm_helper_translate_curve_to_degamma_hw_format` function. The issue could occur when the index 'i' exceeds the number of transfer function points (TRANSFER_FUNC_POINTS). The fix adds a check to ensure 'i' is within bounds before accessing the transfer function points. If 'i' is out of bounds the function returns false to indicate an error. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:594 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:595 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:596 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max Cc: Tom Chung <chiahsuan.chung(a)amd.com> Cc: Rodrigo Siqueira <Rodrigo.Siqueira(a)amd.com> Cc: Roman Li <roman.li(a)amd.com> Cc: Alex Hung <alex.hung(a)amd.com> Cc: Aurabindo Pillai <aurabindo.pillai(a)amd.com> Cc: Harry Wentland <harry.wentland(a)amd.com> Cc: Hamza Mahfooz <hamza.mahfooz(a)amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> Reviewed-by: Tom Chung <chiahsuan.chung(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Liu Chuang <liuchuang40(a)huawei.com> --- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c index bd9bc51983fe..da7aeb9c4632 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c @@ -560,6 +560,8 @@ bool cm_helper_translate_curve_to_degamma_hw_format( i += increment) { if (j == hw_points - 1) break; + if (i >= TRANSFER_FUNC_POINTS) + return false; rgb_resulted[j].red = output_tf->tf_pts.red[i]; rgb_resulted[j].green = output_tf->tf_pts.green[i]; rgb_resulted[j].blue = output_tf->tf_pts.blue[i]; -- 2.34.1

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[PATCH openEuler-1.0-LTS] drm/amd/display: Fix index out of bounds in degamma hardware format translation
by Liu Chuang 29 Oct '24

29 Oct '24

From: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> mainline inclusion from mainline-v6.12-rc1 commit b7e99058eb2e86aabd7a10761e76cae33d22b49f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYR9A CVE: CVE-2024-49894 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- Fixes index out of bounds issue in `cm_helper_translate_curve_to_degamma_hw_format` function. The issue could occur when the index 'i' exceeds the number of transfer function points (TRANSFER_FUNC_POINTS). The fix adds a check to ensure 'i' is within bounds before accessing the transfer function points. If 'i' is out of bounds the function returns false to indicate an error. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:594 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:595 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:596 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max Cc: Tom Chung <chiahsuan.chung(a)amd.com> Cc: Rodrigo Siqueira <Rodrigo.Siqueira(a)amd.com> Cc: Roman Li <roman.li(a)amd.com> Cc: Alex Hung <alex.hung(a)amd.com> Cc: Aurabindo Pillai <aurabindo.pillai(a)amd.com> Cc: Harry Wentland <harry.wentland(a)amd.com> Cc: Hamza Mahfooz <hamza.mahfooz(a)amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> Reviewed-by: Tom Chung <chiahsuan.chung(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> Signed-off-by: Liu Chuang <liuchuang40(a)huawei.com> --- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c index 67a3ba49234e..ad4247061344 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c @@ -482,6 +482,8 @@ bool cm_helper_translate_curve_to_degamma_hw_format( i += increment) { if (j == hw_points - 1) break; + if (i >= TRANSFER_FUNC_POINTS) + return false; rgb_resulted[j].red = output_tf->tf_pts.red[i]; rgb_resulted[j].green = output_tf->tf_pts.green[i]; rgb_resulted[j].blue = output_tf->tf_pts.blue[i]; -- 2.34.1

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[PATCH OLK-5.10] selinux: fix potential counting error in avc_add_xperms_decision()
by Gu Bowen 29 Oct '24

29 Oct '24

From: Zhen Lei <thunder.leizhen(a)huawei.com> stable inclusion from stable-v5.10.225 commit bbcdda4b0d041fc1302d508321720d6d2c42d083 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB0J6P Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 379d9af3f3da2da1bbfa67baf1820c72a080d1f1 upstream. The count increases only when a node is successfully added to the linked list. Cc: stable(a)vger.kernel.org Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls") Signed-off-by: Zhen Lei <thunder.leizhen(a)huawei.com> Acked-by: Stephen Smalley <stephen.smalley.work(a)gmail.com> Signed-off-by: Paul Moore <paul(a)paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Gu Bowen <gubowen5(a)huawei.com> --- security/selinux/avc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 884a014ce2b8..ab71d0948205 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -332,12 +332,12 @@ static int avc_add_xperms_decision(struct avc_node *node, { struct avc_xperms_decision_node *dest_xpd; - node->ae.xp_node->xp.len++; dest_xpd = avc_xperms_decision_alloc(src->used); if (!dest_xpd) return -ENOMEM; avc_copy_xperms_decision(&dest_xpd->xpd, src); list_add(&dest_xpd->xpd_list, &node->ae.xp_node->xpd_head); + node->ae.xp_node->xp.len++; return 0; } -- 2.25.1

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[PATCH OLK-5.10] randomize_kstack: Improve entropy diffusion
by Gu Bowen 29 Oct '24

29 Oct '24

From: Kees Cook <keescook(a)chromium.org> stable inclusion from stable-v6.6.27 commit 300a2b9c2b28282974ee300bb5d5025cbbb1f64c category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB0K55 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit 9c573cd313433f6c1f7236fe64b9b743500c1628 ] The kstack_offset variable was really only ever using the low bits for kernel stack offset entropy. Add a ror32() to increase bit diffusion. Suggested-by: Arnd Bergmann <arnd(a)arndb.de> Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall") Link: https://lore.kernel.org/r/20240309202445.work.165-kees@kernel.org Signed-off-by: Kees Cook <keescook(a)chromium.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Gu Bowen <gubowen5(a)huawei.com> --- include/linux/randomize_kstack.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/randomize_kstack.h b/include/linux/randomize_kstack.h index 91f1b990a3c3..2cfdc53f01f7 100644 --- a/include/linux/randomize_kstack.h +++ b/include/linux/randomize_kstack.h @@ -47,7 +47,7 @@ void *__builtin_alloca(size_t size); if (static_branch_maybe(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, \ &randomize_kstack_offset)) { \ u32 offset = raw_cpu_read(kstack_offset); \ - offset ^= (rand); \ + offset = ror32(offset, 5) ^ (rand); \ raw_cpu_write(kstack_offset, offset); \ } \ } while (0) -- 2.25.1

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[PATCH OLK-6.6] block: fix integer overflow in BLKSECDISCARD
by Zheng Qixing 29 Oct '24

29 Oct '24

From: Alexey Dobriyan <adobriyan(a)gmail.com> mainline inclusion from mainline-v6.12-rc1 commit 697ba0b6ec4ae04afb67d3911799b5e2043b4455 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRAS CVE: CVE-2024-49994 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- I independently rediscovered commit 22d24a544b0d49bbcbd61c8c0eaf77d3c9297155 block: fix overflow in blk_ioctl_discard() but for secure erase. Same problem: uint64_t r[2] = {512, 18446744073709551104ULL}; ioctl(fd, BLKSECDISCARD, r); will enter near infinite loop inside blkdev_issue_secure_erase(): a.out: attempt to access beyond end of device loop0: rw=5, sector=3399043073, nr_sectors = 1024 limit=2048 bio_check_eod: 3286214 callbacks suppressed Signed-off-by: Alexey Dobriyan <adobriyan(a)gmail.com> Link: https://lore.kernel.org/r/9e64057f-650a-46d1-b9f7-34af391536ef@p183 Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Conflicts: block/ioctl.c [The conflict occurs because commit 881494ed031f ("blk_ioctl_{ discard,zeroout}(): we only want ->bd_inode->i_mapping here...") is not introduced.] Signed-off-by: Zheng Qixing <zhengqixing(a)huawei.com> --- block/ioctl.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index 9b1ad8b60923..71b1a185c226 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -115,7 +115,7 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, return -EINVAL; filemap_invalidate_lock(inode->i_mapping); - err = truncate_bdev_range(bdev, mode, start, start + len - 1); + err = truncate_bdev_range(bdev, mode, start, end - 1); if (err) goto fail; err = blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL); @@ -127,7 +127,7 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode, void __user *argp) { - uint64_t start, len; + uint64_t start, len, end; uint64_t range[2]; int err; @@ -142,11 +142,12 @@ static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode, len = range[1]; if ((start & 511) || (len & 511)) return -EINVAL; - if (start + len > bdev_nr_bytes(bdev)) + if (check_add_overflow(start, len, &end) || + end > bdev_nr_bytes(bdev)) return -EINVAL; filemap_invalidate_lock(bdev->bd_inode->i_mapping); - err = truncate_bdev_range(bdev, mode, start, start + len - 1); + err = truncate_bdev_range(bdev, mode, start, end - 1); if (!err) err = blkdev_issue_secure_erase(bdev, start >> 9, len >> 9, GFP_KERNEL); -- 2.39.2

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[PATCH OLK-5.10 v2 0/2] CVE-2024-49955
by liwei 29 Oct '24

29 Oct '24

Armin Wolf (2): ACPI: battery: Simplify battery hook locking ACPI: battery: Fix possible crash when unregistering a battery hook drivers/acpi/battery.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) -- 2.25.1

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[PATCH openEuler-22.03-LTS-SP1 v2 0/2] CVE-2024-49955
by liwei 29 Oct '24

29 Oct '24

Armin Wolf (2): ACPI: battery: Simplify battery hook locking ACPI: battery: Fix possible crash when unregistering a battery hook drivers/acpi/battery.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) -- 2.25.1

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[PATCH OLK-6.6] drm/amd/display: fix double free issue during amdgpu module unload
by liwei 29 Oct '24

29 Oct '24

From: Tim Huang <tim.huang(a)amd.com> mainline inclusion from mainline-v6.12-rc1 commit 20b5a8f9f4670a8503aa9fa95ca632e77c6bf55d category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRDA CVE: CVE-2024-49989 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… ------------------------------------------------- Flexible endpoints use DIGs from available inflexible endpoints, so only the encoders of inflexible links need to be freed. Otherwise, a double free issue may occur when unloading the amdgpu module. [ 279.190523] RIP: 0010:__slab_free+0x152/0x2f0 [ 279.190577] Call Trace: [ 279.190580] <TASK> [ 279.190582] ? show_regs+0x69/0x80 [ 279.190590] ? die+0x3b/0x90 [ 279.190595] ? do_trap+0xc8/0xe0 [ 279.190601] ? do_error_trap+0x73/0xa0 [ 279.190605] ? __slab_free+0x152/0x2f0 [ 279.190609] ? exc_invalid_op+0x56/0x70 [ 279.190616] ? __slab_free+0x152/0x2f0 [ 279.190642] ? asm_exc_invalid_op+0x1f/0x30 [ 279.190648] ? dcn10_link_encoder_destroy+0x19/0x30 [amdgpu] [ 279.191096] ? __slab_free+0x152/0x2f0 [ 279.191102] ? dcn10_link_encoder_destroy+0x19/0x30 [amdgpu] [ 279.191469] kfree+0x260/0x2b0 [ 279.191474] dcn10_link_encoder_destroy+0x19/0x30 [amdgpu] [ 279.191821] link_destroy+0xd7/0x130 [amdgpu] [ 279.192248] dc_destruct+0x90/0x270 [amdgpu] [ 279.192666] dc_destroy+0x19/0x40 [amdgpu] [ 279.193020] amdgpu_dm_fini+0x16e/0x200 [amdgpu] [ 279.193432] dm_hw_fini+0x26/0x40 [amdgpu] [ 279.193795] amdgpu_device_fini_hw+0x24c/0x400 [amdgpu] [ 279.194108] amdgpu_driver_unload_kms+0x4f/0x70 [amdgpu] [ 279.194436] amdgpu_pci_remove+0x40/0x80 [amdgpu] [ 279.194632] pci_device_remove+0x3a/0xa0 [ 279.194638] device_remove+0x40/0x70 [ 279.194642] device_release_driver_internal+0x1ad/0x210 [ 279.194647] driver_detach+0x4e/0xa0 [ 279.194650] bus_remove_driver+0x6f/0xf0 [ 279.194653] driver_unregister+0x33/0x60 [ 279.194657] pci_unregister_driver+0x44/0x90 [ 279.194662] amdgpu_exit+0x19/0x1f0 [amdgpu] [ 279.194939] __do_sys_delete_module.isra.0+0x198/0x2f0 [ 279.194946] __x64_sys_delete_module+0x16/0x20 [ 279.194950] do_syscall_64+0x58/0x120 [ 279.194954] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 279.194980] </TASK> Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira(a)amd.com> Signed-off-by: Tim Huang <tim.huang(a)amd.com> Reviewed-by: Roman Li <roman.li(a)amd.com> Signed-off-by: Roman Li <roman.li(a)amd.com> Tested-by: Daniel Wheeler <daniel.wheeler(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> Signed-off-by: liwei <liwei728(a)huawei.com> --- drivers/gpu/drm/amd/display/dc/link/link_factory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/link/link_factory.c b/drivers/gpu/drm/amd/display/dc/link/link_factory.c index 33bb96f770b8..eb7c9f226af5 100644 --- a/drivers/gpu/drm/amd/display/dc/link/link_factory.c +++ b/drivers/gpu/drm/amd/display/dc/link/link_factory.c @@ -403,7 +403,7 @@ static void link_destruct(struct dc_link *link) if (link->panel_cntl) link->panel_cntl->funcs->destroy(&link->panel_cntl); - if (link->link_enc) { + if (link->link_enc && !link->is_dig_mapping_flexible) { /* Update link encoder resource tracking variables. These are used for * the dynamic assignment of link encoders to streams. Virtual links * are not assigned encoder resources on creation. -- 2.25.1

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[PATCH OLK-6.6] nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
by Zhang Kunbo 29 Oct '24

29 Oct '24

From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> stable inclusion from stable-v6.6.54 commit 21839b6fbc3c41b3e374ecbdb0cabbbb2c53cf34 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYPKK CVE: CVE-2024-47699 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit 9403001ad65ae4f4c5de368bdda3a0636b51d51a ] Patch series "nilfs2: fix potential issues with empty b-tree nodes". This series addresses three potential issues with empty b-tree nodes that can occur with corrupted filesystem images, including one recently discovered by syzbot. This patch (of 3): If a b-tree is broken on the device, and the b-tree height is greater than 2 (the level of the root node is greater than 1) even if the number of child nodes of the b-tree root is 0, a NULL pointer dereference occurs in nilfs_btree_prepare_insert(), which is called from nilfs_btree_insert(). This is because, when the number of child nodes of the b-tree root is 0, nilfs_btree_do_lookup() does not set the block buffer head in any of path[x].bp_bh, leaving it as the initial value of NULL, but if the level of the b-tree root node is greater than 1, nilfs_btree_get_nonroot_node(), which accesses the buffer memory of path[x].bp_bh, is called. Fix this issue by adding a check to nilfs_btree_root_broken(), which performs sanity checks when reading the root node from the device, to detect this inconsistency. Thanks to Lizhi Xu for trying to solve the bug and clarifying the cause early on. Link: https://lkml.kernel.org/r/20240904081401.16682-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20240902084101.138971-1-lizhi.xu@windriver.com Link: https://lkml.kernel.org/r/20240904081401.16682-2-konishi.ryusuke@gmail.com Fixes: 17c76b0104e4 ("nilfs2: B-tree based block mapping") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+9bff4c7b992038a7409f(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9bff4c7b992038a7409f Cc: Lizhi Xu <lizhi.xu(a)windriver.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Zhang Kunbo <zhangkunbo(a)huawei.com> --- fs/nilfs2/btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index 598f05867059..fa51ed649968 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -381,7 +381,8 @@ static int nilfs_btree_root_broken(const struct nilfs_btree_node *node, if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN || level >= NILFS_BTREE_LEVEL_MAX || nchildren < 0 || - nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX)) { + nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX || + (nchildren == 0 && level > NILFS_BTREE_LEVEL_NODE_MIN))) { nilfs_crit(inode->i_sb, "bad btree root (ino=%lu): level = %d, flags = 0x%x, nchildren = %d", inode->i_ino, level, flags, nchildren); -- 2.34.1

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[PATCH openEuler-22.03-LTS-SP1] nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
by Zhang Kunbo 29 Oct '24

29 Oct '24

From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> stable inclusion from stable-v5.10.227 commit 24bf40740a3da6b4056721da34997ae6938f3da1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYPKK CVE: CVE-2024-47699 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… ------------------------------------------------- [ Upstream commit 9403001ad65ae4f4c5de368bdda3a0636b51d51a ] Patch series "nilfs2: fix potential issues with empty b-tree nodes". This series addresses three potential issues with empty b-tree nodes that can occur with corrupted filesystem images, including one recently discovered by syzbot. This patch (of 3): If a b-tree is broken on the device, and the b-tree height is greater than 2 (the level of the root node is greater than 1) even if the number of child nodes of the b-tree root is 0, a NULL pointer dereference occurs in nilfs_btree_prepare_insert(), which is called from nilfs_btree_insert(). This is because, when the number of child nodes of the b-tree root is 0, nilfs_btree_do_lookup() does not set the block buffer head in any of path[x].bp_bh, leaving it as the initial value of NULL, but if the level of the b-tree root node is greater than 1, nilfs_btree_get_nonroot_node(), which accesses the buffer memory of path[x].bp_bh, is called. Fix this issue by adding a check to nilfs_btree_root_broken(), which performs sanity checks when reading the root node from the device, to detect this inconsistency. Thanks to Lizhi Xu for trying to solve the bug and clarifying the cause early on. Link: https://lkml.kernel.org/r/20240904081401.16682-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20240902084101.138971-1-lizhi.xu@windriver.com Link: https://lkml.kernel.org/r/20240904081401.16682-2-konishi.ryusuke@gmail.com Fixes: 17c76b0104e4 ("nilfs2: B-tree based block mapping") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+9bff4c7b992038a7409f(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9bff4c7b992038a7409f Cc: Lizhi Xu <lizhi.xu(a)windriver.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Zhang Kunbo <zhangkunbo(a)huawei.com> --- fs/nilfs2/btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index 90842645328b..94cffa0e7065 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -381,7 +381,8 @@ static int nilfs_btree_root_broken(const struct nilfs_btree_node *node, if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN || level >= NILFS_BTREE_LEVEL_MAX || nchildren < 0 || - nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX)) { + nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX || + (nchildren == 0 && level > NILFS_BTREE_LEVEL_NODE_MIN))) { nilfs_crit(inode->i_sb, "bad btree root (ino=%lu): level = %d, flags = 0x%x, nchildren = %d", inode->i_ino, level, flags, nchildren); -- 2.34.1

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