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Re: 回复: 转发: 请教一下，想提交一个内核的补丁，怎么操作，谢谢。（补丁内容见内）
by chengjian (D) 30 Aug '21

30 Aug '21

On 2021/8/30 9:13, 徐力群 wrote: > > 这个是增加了bugzilla链接地址的补丁，之前可能重复发了几次（一直以为发送失败了）。谢谢。 > 您好，冒昧打扰，您订阅邮件列表了么。如果没订阅邮件列表，您的邮件可能被当作垃圾邮件墙掉。

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[PATCH openEuler-1.0-LTS] mm, vmscan: guarantee drop_slab_node() termination
by Yang Yingliang 28 Aug '21

28 Aug '21

From: Vlastimil Babka <vbabka(a)suse.cz> mainline inclusion from linux-next commit 0b8efcb0bf057dc0203a022334d5934867a6c212 category: bugfix bugzilla: 175105 CVE: NA ------------------------------------------------- drop_slab_node() is called as part of echo 2>/proc/sys/vm/drop_caches operation. It iterates over all memcgs and calls shrink_slab() which in turn iterates over all slab shrinkers. Freed objects are counted and as long as the total number of freed objects from all memcgs and shrinkers is higher than 10, drop_slab_node() loops for another full memcgs*shrinkers iteration. This arbitrary constant threshold of 10 can result in effectively an infinite loop on a system with large number of memcgs and/or parallel activity that allocates new objects. This has been reported previously by Chunxin Zang [1] and recently by our customer. The previous report [1] has resulted in commit 069c411de40a ("mm/vmscan: fix infinite loop in drop_slab_node") which added a check for signals allowing the user to terminate the command writing to drop_caches. At the time it was also considered to make the threshold grow with each iteration to guarantee termination, but such patch hasn't been formally proposed yet. This patch implements the dynamically growing threshold. At first iteration it's enough to free one object to continue, and this threshold effectively doubles with each iteration. Our customer's feedback was positive. There is always a risk that this change will result on some system in a previously terminating drop_caches operation to terminate sooner and free fewer objects. Ideally the semantics would guarantee freeing all freeable objects that existed at the moment of starting the operation, while not looping forever for newly allocated objects, but that's not feasible to track. In the less ideal solution based on thresholds, arguably the termination guarantee is more important than the exhaustiveness guarantee. If there are reports of large regression wrt being exhaustive, we can tune how fast the threshold grows. [1] https://lore.kernel.org/lkml/20200909152047.27905-1-zangchunxin@bytedance.c… Matthew reports [2] that if we free enough objects, we can eventually right-shift by BITS_PER_LONG, which is undefined behavior. Raise the threshold from 0 to 1 which means we will shift only up to BITS_PER_LONG-1. [2] https://lore.kernel.org/linux-mm/YSTDnqKgQLvziyQI@casper.infradead.org/ Link: https://lkml.kernel.org/r/20210818152239.25502-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz> Reported-by: Chunxin Zang <zangchunxin(a)bytedance.com> Cc: Muchun Song <songmuchun(a)bytedance.com> Cc: Chris Down <chris(a)chrisdown.name> Cc: Michal Hocko <mhocko(a)kernel.org> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr(a)canb.auug.org.au> Conflicts: mm/vmscan.c Signed-off-by: Liu Shixin <liushixin2(a)huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- mm/vmscan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index b5f5a366d155f..b381c891ca8fd 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -738,6 +738,7 @@ void drop_slab_node(int nid) { unsigned long freed; unsigned int counts = 0; + int shift = 0; do { struct mem_cgroup *memcg = NULL; @@ -760,7 +761,7 @@ void drop_slab_node(int nid) return; } } - } while (freed > 10); + } while ((freed >> shift++) > 1); } void drop_slab(void) -- 2.25.1

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[PATCH openEuler-1.0-LTS] jump_label: skip resource release if jump label is not relocated
by Yang Yingliang 28 Aug '21

28 Aug '21

From: Ye Weihua <yeweihua4(a)huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I47NHU CVE: NA -------------------------------- Before a module is deleted, the kernel traverses the jump_label section to release resources applied by each jump entry. Common modules apply for these resources before module initialization, but livepatch modules apply during livepatch redirection. Therefore, when a livepatch module fails to be inserted, the resources to be applied by jump_label are not applied. As a result, a panic occurs when a null pointer is accessed during resource release. To solve the this problem, skip resource release if jump label is not relocated. Signed-off-by: Ye Weihua <yeweihua4(a)huawei.com> Reviewed-by: Yang Jihong <yangjihong1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- kernel/jump_label.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 0cf0a14969254..15c7df2065511 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -623,6 +623,9 @@ static void jump_label_del_module(struct module *mod) struct static_key *key = NULL; struct static_key_mod *jlm, **prev; + if (unlikely(!mod_klp_rel_completed(mod))) + return; + for (iter = iter_start; iter < iter_stop; iter++) { if (jump_entry_key(iter) == key) continue; -- 2.25.1

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[PATCH openEuler-1.0-LTS 1/4] ext4: make the updating inode data procedure atomic
by Yang Yingliang 28 Aug '21

28 Aug '21

From: Zhang Yi <yi.zhang(a)huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I476C7 CVE: NA --------------------------- Now that ext4_do_update_inode() return error before filling the whole inode data if we fail to set inode blocks in ext4_inode_blocks_set(). This error should never happen in theory since sb->s_maxbytes should not have allowed this, we have already init sb->s_maxbytes according to this feature in ext4_fill_super(). So even through that could only happen due to the filesystem corruption, we'd better to return after we finish updating the inode because it may left an uninitialized buffer and we could read this buffer later in "errors=continue" mode. This patch make the updating inode data procedure atomic, call EXT4_ERROR_INODE() after we dropping i_raw_lock after something bad happened, make sure that the inode is integrated, and also drop a BUG_ON and do some small cleanups. Link: https://lore.kernel.org/linux-ext4/20210821065450.1397451-4-yi.zhang@huawei… Signed-off-by: Zhang Yi <yi.zhang(a)huawei.com> Reviewed-by: Jan Kara <jack(a)suse.cz> Reviewed-by: Yang Erkun <yangerkun(a)huawei.com> Reviewed-by: Xie Miao <miaoxie(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- fs/ext4/inode.c | 44 ++++++++++++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 16 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index b809d383cc5ae..a032f211b80cf 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5169,8 +5169,14 @@ static int ext4_inode_blocks_set(handle_t *handle, ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); return 0; } + + /* + * This should never happen since sb->s_maxbytes should not have + * allowed this, sb->s_maxbytes was set according to the huge_file + * feature in ext4_fill_super(). + */ if (!ext4_has_feature_huge_file(sb)) - return -EFBIG; + return -EFSCORRUPTED; if (i_blocks <= 0xffffffffffffULL) { /* @@ -5277,16 +5283,14 @@ static int ext4_do_update_inode(handle_t *handle, spin_lock(&ei->i_raw_lock); - /* For fields not tracked in the in-memory inode, - * initialise them to zero for new inodes. */ + /* + * For fields not tracked in the in-memory inode, initialise them + * to zero for new inodes. + */ if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); err = ext4_inode_blocks_set(handle, raw_inode, ei); - if (err) { - spin_unlock(&ei->i_raw_lock); - goto out_brelse; - } raw_inode->i_mode = cpu_to_le16(inode->i_mode); i_uid = i_uid_read(inode); @@ -5295,10 +5299,11 @@ static int ext4_do_update_inode(handle_t *handle, if (!(test_opt(inode->i_sb, NO_UID32))) { raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid)); raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid)); -/* - * Fix up interoperability with old kernels. Otherwise, old inodes get - * re-used with the upper 16 bits of the uid/gid intact - */ + /* + * Fix up interoperability with old kernels. Otherwise, + * old inodes get re-used with the upper 16 bits of the + * uid/gid intact. + */ if (ei->i_dtime && list_empty(&ei->i_orphan)) { raw_inode->i_uid_high = 0; raw_inode->i_gid_high = 0; @@ -5367,8 +5372,9 @@ static int ext4_do_update_inode(handle_t *handle, } } - BUG_ON(!ext4_has_feature_project(inode->i_sb) && - i_projid != EXT4_DEF_PROJID); + if (i_projid != EXT4_DEF_PROJID && + !ext4_has_feature_project(inode->i_sb)) + err = err ?: -EFSCORRUPTED; if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) @@ -5376,6 +5382,11 @@ static int ext4_do_update_inode(handle_t *handle, ext4_inode_csum_set(inode, raw_inode, ei); spin_unlock(&ei->i_raw_lock); + if (err) { + EXT4_ERROR_INODE(inode, "corrupted inode contents"); + goto out_brelse; + } + if (inode->i_sb->s_flags & SB_LAZYTIME) ext4_update_other_inodes_time(inode->i_sb, inode->i_ino, bh->b_data); @@ -5383,13 +5394,13 @@ static int ext4_do_update_inode(handle_t *handle, BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_metadata(handle, NULL, bh); if (err) - goto out_brelse; + goto out_error; ext4_clear_inode_state(inode, EXT4_STATE_NEW); if (set_large_file) { BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access"); err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); if (err) - goto out_brelse; + goto out_error; lock_buffer(EXT4_SB(sb)->s_sbh); ext4_set_feature_large_file(sb); ext4_superblock_csum_set(sb); @@ -5399,9 +5410,10 @@ static int ext4_do_update_inode(handle_t *handle, EXT4_SB(sb)->s_sbh); } ext4_update_inode_fsync_trans(handle, inode, need_datasync); +out_error: + ext4_std_error(inode->i_sb, err); out_brelse: brelse(bh); - ext4_std_error(inode->i_sb, err); return err; } -- 2.25.1

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Re: 转发: 请教一下，想提交一个内核的补丁，怎么操作，谢谢。（补丁内容见内）
by Xie XiuQi 27 Aug '21

27 Aug '21

你好，非常欢迎参与 openEuler kernel 开发。首先在这里提交 issue，描述下要解决什么问题。 https://gitee.com/openeuler/kernel/issues 补丁的 Commit Message 中附上对应的 issue 链接，如在bugzila 行添加： bugzilla: https://gitee.com/openeuler/kernel/issues/I3DJ83 然后将适配之后的补丁发往 kernel(a)openeuler.org, 有问题可以联系我或 Cheng Jian. --- Xie XiuQi On 2021/8/27 14:18, 徐力群 wrote: > > > > > > *发件人:*徐力群 > *发送时间:*2021年8月27日14:18 > *收件人:*kernel-owner@openeuler.org；<kernel-owner(a)openeuler.org;>; kernel(a)openeuler.org > *主题:*请教一下，想提交一个内核的补丁，怎么操作，谢谢。（补丁内容见内） > > > > 该补丁打上之后，guest如果删除了磁盘的文件，那么从host上看磁盘文件会变小。 > > > > > > > > virtio_blk: add discard and write zeroes support > > > > mainline inclusion > > from mainline-5.14-rc7 > > commit 1f23816b8eb8fdc39990abe166c10a18c16f6b21、af822aa68fbdf0a480a17462ed70232998127453 > > category: bugfix > > bugzilla: NA > > CVE: NA > > > > ------------------------------------------------- > > from： > > https://github.com/torvalds/linux/commit/1f23816b8eb8fdc39990abe166c10a18c1… <https://github.com/torvalds/linux/commit/1f23816b8eb8fdc39990abe166c10a18c1…> > > https://github.com/torvalds/linux/commit/af822aa68fbdf0a480a17462ed70232998… <https://github.com/torvalds/linux/commit/af822aa68fbdf0a480a17462ed70232998…> > > > > In commit 88c85538, "virtio-blk: add discard and write zeroes features > > to specification" (https://github.com/oasis-tcs/virtio-spec <https://github.com/oasis-tcs/virtio-spec>), the virtio > > block specification has been extended to add VIRTIO_BLK_T_DISCARD and > > VIRTIO_BLK_T_WRITE_ZEROES commands. This patch enables support for > > discard and write zeroes in the virtio-blk driver when the device > > advertises the corresponding features, VIRTIO_BLK_F_DISCARD and > > VIRTIO_BLK_F_WRITE_ZEROES. >

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[PATCH openEuler-21.03] proc: Track /proc/$pid/attr/ opener mm_struct
by bobo~ 27 Aug '21

27 Aug '21

From: Kees Cook <keescook(a)chromium.org> stable inclusion from stable-v5.10.44 commit f70102cb369cde6ab7551ca58152d00fd3478fec bugzilla: CVE: NA -------------------------------- commit 591a22c14d3f45cc38bd1931c593c221df2f1881 upstream. Commit bfb819ea20ce ("proc: Check /proc/$pid/attr/ writes against file opener") tried to make sure that there could not be a confusion between the opener of a /proc/$pid/attr/ file and the writer. It used struct cred to make sure the privileges didn't change. However, there were existing cases where a more privileged thread was passing the opened fd to a differently privileged thread (during container setup). Instead, use mm_struct to track whether the opener and writer are still the same process. (This is what several other proc files already do, though for different reasons.) Reported-by: Christian Brauner <christian.brauner(a)ubuntu.com> Reported-by: Andrea Righi <andrea.righi(a)canonical.com> Tested-by: Andrea Righi <andrea.righi(a)canonical.com> Fixes: bfb819ea20ce ("proc: Check /proc/$pid/attr/ writes against file opener") Cc: stable(a)vger.kernel.org Signed-off-by: Kees Cook <keescook(a)chromium.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: bobo~ <931671772(a)qq.com> --- fs/proc/base.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 720e2e524cb1..a2d472b0c2e3 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2691,6 +2691,11 @@ static int proc_pident_readdir(struct file *file, struct dir_context *ctx, } #ifdef CONFIG_SECURITY +static int proc_pid_attr_open(struct inode *inode, struct file *file) +{ + return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); +} + static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { @@ -2721,7 +2726,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, int rv; /* A task may only write when it was the opener. */ - if (file->f_cred != current_real_cred()) + if (file->private_data != current->mm) return -EPERM; rcu_read_lock(); @@ -2771,9 +2776,11 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, } static const struct file_operations proc_pid_attr_operations = { + .open = proc_pid_attr_open, .read = proc_pid_attr_read, .write = proc_pid_attr_write, .llseek = generic_file_llseek, + .release = mem_release, }; #define LSM_DIR_OPS(LSM) \ -- 2.23.0

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(no subject)
by bobo~ 27 Aug '21

27 Aug '21

From f70102cb369cde6ab7551ca58152d00fd3478fec Mon Sep 17 00:00:00 2001 From: Kees Cook <keescook(a)chromium.org> Date: Tue, 8 Jun 2021 10:12:21 -0700 Subject: [PATCH] proc: Track /proc/$pid/attr/ opener mm_struct stable inclusion from stable-v5.10.44 commit f70102cb369cde6ab7551ca58152d00fd3478fec bugzilla: CVE: NA -------------------------------- commit 591a22c14d3f45cc38bd1931c593c221df2f1881 upstream. Commit bfb819ea20ce ("proc: Check /proc/$pid/attr/ writes against file opener") tried to make sure that there could not be a confusion between the opener of a /proc/$pid/attr/ file and the writer. It used struct cred to make sure the privileges didn't change. However, there were existing cases where a more privileged thread was passing the opened fd to a differently privileged thread (during container setup). Instead, use mm_struct to track whether the opener and writer are still the same process. (This is what several other proc files already do, though for different reasons.) Reported-by: Christian Brauner <christian.brauner(a)ubuntu.com> Reported-by: Andrea Righi <andrea.righi(a)canonical.com> Tested-by: Andrea Righi <andrea.righi(a)canonical.com> Fixes: bfb819ea20ce ("proc: Check /proc/$pid/attr/ writes against file opener") Cc: stable(a)vger.kernel.org Signed-off-by: Kees Cook <keescook(a)chromium.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- fs/proc/base.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 297ea12b3cfd..511d98d09754 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2675,6 +2675,11 @@ static int proc_pident_readdir(struct file *file, struct dir_context *ctx, } #ifdef CONFIG_SECURITY +static int proc_pid_attr_open(struct inode *inode, struct file *file) +{ + return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS); +} + static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { @@ -2705,7 +2710,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, int rv; /* A task may only write when it was the opener. */ - if (file->f_cred != current_real_cred()) + if (file->private_data != current->mm) return -EPERM; rcu_read_lock(); @@ -2755,9 +2760,11 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, } static const struct file_operations proc_pid_attr_operations = { + .open = proc_pid_attr_open, .read = proc_pid_attr_read, .write = proc_pid_attr_write, .llseek = generic_file_llseek, + .release = mem_release, }; #define LSM_DIR_OPS(LSM) \ -- 2.25.1

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[PATCH openEuler-21.09 1/2] mm: fix oom killing for disabled pid
by Zheng Zengkai 26 Aug '21

26 Aug '21

From: Jing Xiangfeng <jingxiangfeng(a)huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I46IUJ CVE: NA -------------------------------------- In oom_next_task(), if points is equal to LONG_MIN, then we choose it to kill. That is not correct. LONG_MIN means to disable killing it. So fix it. Fixes: 4da32073a8fe ("memcg: support priority for oom") Signed-off-by: Jing Xiangfeng <jingxiangfeng(a)huawei.com> Reviewed-by: Chen Wandun <chenwandun(a)huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai(a)huawei.com> --- mm/oom_kill.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 41668bd37f52..fb39b0902476 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -311,15 +311,15 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc) * choose the task with the highest number of 'points'. */ static bool oom_next_task(struct task_struct *task, struct oom_control *oc, - unsigned long points) + long points) { struct mem_cgroup *cur_memcg; struct mem_cgroup *oc_memcg; if (!static_branch_likely(&memcg_qos_stat_key)) - return !points || points < oc->chosen_points; + return (points == LONG_MIN || points < oc->chosen_points); - if (!points) + if (points == LONG_MIN) return true; if (!oc->chosen) @@ -341,9 +341,9 @@ static bool oom_next_task(struct task_struct *task, struct oom_control *oc, } #else static inline bool oom_next_task(struct task_struct *task, - struct oom_control *oc, unsigned long points) + struct oom_control *oc, long points) { - return !points || points < oc->chosen_points; + return (points == LONG_MIN || points < oc->chosen_points); } #endif -- 2.20.1

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[PATCH openEuler-1.0-LTS] KVM: X86: MMU: Use the correct inherited permissions to get shadow page
by Yang Yingliang 26 Aug '21

26 Aug '21

From: Lai Jiangshan <laijs(a)linux.alibaba.com> stable inclusion from linux-4.19.204 commit 4c07e70141eebd3db64297515a427deea4822957 CVE: CVE-2021-38198 -------------------------------- commit b1bd5cba3306691c771d558e94baa73e8b0b96b7 upstream. When computing the access permissions of a shadow page, use the effective permissions of the walk up to that point, i.e. the logic AND of its parents' permissions. Two guest PxE entries that point at the same table gfn need to be shadowed with different shadow pages if their parents' permissions are different. KVM currently uses the effective permissions of the last non-leaf entry for all non-leaf entries. Because all non-leaf SPTEs have full ("uwx") permissions, and the effective permissions are recorded only in role.access and merged into the leaves, this can lead to incorrect reuse of a shadow page and eventually to a missing guest protection page fault. For example, here is a shared pagetable: pgd[] pud[] pmd[] virtual address pointers /->pmd1(u--)->pte1(uw-)->page1 <- ptr1 (u--) /->pud1(uw-)--->pmd2(uw-)->pte2(uw-)->page2 <- ptr2 (uw-) pgd-| (shared pmd[] as above) \->pud2(u--)--->pmd1(u--)->pte1(uw-)->page1 <- ptr3 (u--) \->pmd2(uw-)->pte2(uw-)->page2 <- ptr4 (u--) pud1 and pud2 point to the same pmd table, so: - ptr1 and ptr3 points to the same page. - ptr2 and ptr4 points to the same page. (pud1 and pud2 here are pud entries, while pmd1 and pmd2 here are pmd entries) - First, the guest reads from ptr1 first and KVM prepares a shadow page table with role.access=u--, from ptr1's pud1 and ptr1's pmd1. "u--" comes from the effective permissions of pgd, pud1 and pmd1, which are stored in pt->access. "u--" is used also to get the pagetable for pud1, instead of "uw-". - Then the guest writes to ptr2 and KVM reuses pud1 which is present. The hypervisor set up a shadow page for ptr2 with pt->access is "uw-" even though the pud1 pmd (because of the incorrect argument to kvm_mmu_get_page in the previous step) has role.access="u--". - Then the guest reads from ptr3. The hypervisor reuses pud1's shadow pmd for pud2, because both use "u--" for their permissions. Thus, the shadow pmd already includes entries for both pmd1 and pmd2. - At last, the guest writes to ptr4. This causes no vmexit or pagefault, because pud1's shadow page structures included an "uw-" page even though its role.access was "u--". Any kind of shared pagetable might have the similar problem when in virtual machine without TDP enabled if the permissions are different from different ancestors. In order to fix the problem, we change pt->access to be an array, and any access in it will not include permissions ANDed from child ptes. The test code is: https://lore.kernel.org/kvm/20210603050537.19605-1-jiangshanlai@gmail.com/ Remember to test it with TDP disabled. The problem had existed long before the commit 41074d07c78b ("KVM: MMU: Fix inherited permissions for emulated guest pte updates"), and it is hard to find which is the culprit. So there is no fixes tag here. Signed-off-by: Lai Jiangshan <laijs(a)linux.alibaba.com> Message-Id: <20210603052455.21023-1-jiangshanlai(a)gmail.com> Cc: stable(a)vger.kernel.org Fixes: cea0f0e7ea54 ("[PATCH] KVM: MMU: Shadow page table caching") Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> [OP: - apply arch/x86/kvm/mmu/* changes to arch/x86/kvm - apply documentation changes to Documentation/virtual/kvm/mmu.txt - adjusted context in arch/x86/kvm/paging_tmpl.h] Signed-off-by: Ovidiu Panait <ovidiu.panait(a)windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- Documentation/virtual/kvm/mmu.txt | 4 ++-- arch/x86/kvm/paging_tmpl.h | 14 +++++++++----- 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt index e507a9e0421ed..851a8abcadce4 100644 --- a/Documentation/virtual/kvm/mmu.txt +++ b/Documentation/virtual/kvm/mmu.txt @@ -152,8 +152,8 @@ Shadow pages contain the following information: shadow pages) so role.quadrant takes values in the range 0..3. Each quadrant maps 1GB virtual address space. role.access: - Inherited guest access permissions in the form uwx. Note execute - permission is positive, not negative. + Inherited guest access permissions from the parent ptes in the form uwx. + Note execute permission is positive, not negative. role.invalid: The page is invalid and should not be used. It is a root page that is currently pinned (by a cpu hardware register pointing to it); once it is diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index adf42dc8d38b0..31014a746aede 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -93,8 +93,8 @@ struct guest_walker { gpa_t pte_gpa[PT_MAX_FULL_LEVELS]; pt_element_t __user *ptep_user[PT_MAX_FULL_LEVELS]; bool pte_writable[PT_MAX_FULL_LEVELS]; - unsigned pt_access; - unsigned pte_access; + unsigned int pt_access[PT_MAX_FULL_LEVELS]; + unsigned int pte_access; gfn_t gfn; struct x86_exception fault; }; @@ -388,13 +388,15 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker, } walker->ptes[walker->level - 1] = pte; + + /* Convert to ACC_*_MASK flags for struct guest_walker. */ + walker->pt_access[walker->level - 1] = FNAME(gpte_access)(pt_access ^ walk_nx_mask); } while (!is_last_gpte(mmu, walker->level, pte)); pte_pkey = FNAME(gpte_pkeys)(vcpu, pte); accessed_dirty = have_ad ? pte_access & PT_GUEST_ACCESSED_MASK : 0; /* Convert to ACC_*_MASK flags for struct guest_walker. */ - walker->pt_access = FNAME(gpte_access)(pt_access ^ walk_nx_mask); walker->pte_access = FNAME(gpte_access)(pte_access ^ walk_nx_mask); errcode = permission_fault(vcpu, mmu, walker->pte_access, pte_pkey, access); if (unlikely(errcode)) @@ -432,7 +434,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker, } pgprintk("%s: pte %llx pte_access %x pt_access %x\n", - __func__, (u64)pte, walker->pte_access, walker->pt_access); + __func__, (u64)pte, walker->pte_access, + walker->pt_access[walker->level - 1]); return 1; error: @@ -601,7 +604,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, { struct kvm_mmu_page *sp = NULL; struct kvm_shadow_walk_iterator it; - unsigned direct_access, access = gw->pt_access; + unsigned int direct_access, access; int top_level, ret; gfn_t gfn, base_gfn; @@ -633,6 +636,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, sp = NULL; if (!is_shadow_present_pte(*it.sptep)) { table_gfn = gw->table_gfn[it.level - 2]; + access = gw->pt_access[it.level - 2]; sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1, false, access); } -- 2.25.1

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[PATCH kernel-4.19] x86/config: Enable CONFIG_USERSWAP for openeuler_defconfig
by Yang Yingliang 26 Aug '21

26 Aug '21

From: Xiongfeng Wang <wangxiongfeng2(a)huawei.com> hulk inclusion category: feature bugzilla: 47439 CVE: NA ------------------------------------------------- Enable CONFIG_USERSWAP for openeuler_defconfig Signed-off-by: Xiongfeng Wang <wangxiongfeng2(a)huawei.com> Reviewed-by: tong tiangen <tongtiangen(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- arch/x86/configs/openeuler_defconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/configs/openeuler_defconfig b/arch/x86/configs/openeuler_defconfig index 80f5769d2cc5a..4e33229af5e26 100644 --- a/arch/x86/configs/openeuler_defconfig +++ b/arch/x86/configs/openeuler_defconfig @@ -1005,6 +1005,7 @@ CONFIG_TRANSPARENT_HUGE_PAGECACHE=y CONFIG_CLEANCACHE=y CONFIG_FRONTSWAP=y CONFIG_SHRINK_PAGECACHE=y +CONFIG_USERSWAP=y # CONFIG_CMA is not set CONFIG_MEM_SOFT_DIRTY=y CONFIG_ZSWAP=y -- 2.25.1

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