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[PATCH AUTOSEL 4.14 01/67] cifs: check if SMB2 PDU size has been padded and suppress the warning

by Sasha Levin

From: Ronnie Sahlberg <lsahlber(a)redhat.com> [ Upstream commit e6c47dd0da1e3a484e778046fc10da0b20606a86 ] Some SMB2/3 servers, Win2016 but possibly others too, adds padding not only between PDUs in a compound but also to the final PDU. This padding extends the PDU to a multiple of 8 bytes. Check if the unexpected length looks like this might be the case and avoid triggering the log messages for : "SMB2 server sent bad RFC1001 len %d not %d\n" Signed-off-by: Ronnie Sahlberg <lsahlber(a)redhat.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> Signed-off-by: Sasha Levin <alexander.levin(a)microsoft.com> --- fs/cifs/smb2misc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index 7b08a1446a7f..efdfdb47a7dd 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -211,6 +211,13 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr) if (clc_len == 4 + len + 1) return 0; + /* + * Some windows servers (win2016) will pad also the final + * PDU in a compound to 8 bytes. + */ + if (((clc_len + 7) & ~7) == len) + return 0; + /* * MacOS server pads after SMB2.1 write response with 3 bytes * of junk. Other servers match RFC1001 len to actual -- 2.17.1

7 years, 2 months

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[PATCH v4.14.y] autofs: fix autofs_sbi() does not check super block type

by Zubin Mithra

From: Ian Kent <raven(a)themaw.net> commit 0633da48f0793aeba27f82d30605624416723a91 upstream. autofs_sbi() does not check the superblock magic number to verify it has been given an autofs super block. Backport Note: autofs4 has been renamed to autofs upstream. As a result the upstream patch does not apply cleanly onto 4.14.y. Change-Id: I7194ca9b851fba81f0e20cc4873717ceccaa0b27 Link: http://lkml.kernel.org/r/153475422934.17131.7563724552005298277.stgit@pluto… Reported-by: <syzbot+87c3c541582e56943277(a)syzkaller.appspotmail.com> Signed-off-by: Ian Kent <raven(a)themaw.net> Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Zubin Mithra <zsm(a)chromium.org> --- fs/autofs4/autofs_i.h | 4 +++- fs/autofs4/inode.c | 1 - 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 4737615f0eaa..ce696d6c4641 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -26,6 +26,7 @@ #include <linux/list.h> #include <linux/completion.h> #include <asm/current.h> +#include <linux/magic.h> /* This is the range of ioctl() numbers we claim as ours */ #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY @@ -124,7 +125,8 @@ struct autofs_sb_info { static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb) { - return (struct autofs_sb_info *)(sb->s_fs_info); + return sb->s_magic != AUTOFS_SUPER_MAGIC ? + NULL : (struct autofs_sb_info *)(sb->s_fs_info); } static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry) diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c index 09e7d68dff02..3c7e727612fa 100644 --- a/fs/autofs4/inode.c +++ b/fs/autofs4/inode.c @@ -14,7 +14,6 @@ #include <linux/pagemap.h> #include <linux/parser.h> #include <linux/bitops.h> -#include <linux/magic.h> #include "autofs_i.h" #include <linux/module.h> -- 2.19.0.rc0.228.g281dcd1b4d0-goog

7 years, 2 months

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FAILED: patch "[PATCH] ext4: fix race when setting the bitmap corrupted flag" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9af0b3d1257756394ebbd06b14937b557e3a756b Mon Sep 17 00:00:00 2001 From: Wang Shilong <wshilong(a)ddn.com> Date: Sun, 29 Jul 2018 17:27:45 -0400 Subject: [PATCH] ext4: fix race when setting the bitmap corrupted flag Whenever we hit block or inode bitmap corruptions we set bit and then reduce this block group free inode/clusters counter to expose right available space. However some of ext4_mark_group_bitmap_corrupted() is called inside group spinlock, some are not, this could make it happen that we double reduce one block group free counters from system. Always hold group spinlock for it could fix it, but it looks a little heavy, we could use test_and_set_bit() to fix race problems here. Signed-off-by: Wang Shilong <wshilong(a)ddn.com> Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d4a218ba626c..f7750bc5b85a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -795,26 +795,26 @@ void ext4_mark_group_bitmap_corrupted(struct super_block *sb, struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_group_info *grp = ext4_get_group_info(sb, group); struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL); + int ret; - if ((flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) && - !EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) { - percpu_counter_sub(&sbi->s_freeclusters_counter, - grp->bb_free); - set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, - &grp->bb_state); + if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) { + ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, + &grp->bb_state); + if (!ret) + percpu_counter_sub(&sbi->s_freeclusters_counter, + grp->bb_free); } - if ((flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) && - !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { - if (gdp) { + if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) { + ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, + &grp->bb_state); + if (!ret && gdp) { int count; count = ext4_free_inodes_count(sb, gdp); percpu_counter_sub(&sbi->s_freeinodes_counter, count); } - set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, - &grp->bb_state); } }

7 years, 2 months

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FAILED: patch "[PATCH] ext4: fix race when setting the bitmap corrupted flag" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9af0b3d1257756394ebbd06b14937b557e3a756b Mon Sep 17 00:00:00 2001 From: Wang Shilong <wshilong(a)ddn.com> Date: Sun, 29 Jul 2018 17:27:45 -0400 Subject: [PATCH] ext4: fix race when setting the bitmap corrupted flag Whenever we hit block or inode bitmap corruptions we set bit and then reduce this block group free inode/clusters counter to expose right available space. However some of ext4_mark_group_bitmap_corrupted() is called inside group spinlock, some are not, this could make it happen that we double reduce one block group free counters from system. Always hold group spinlock for it could fix it, but it looks a little heavy, we could use test_and_set_bit() to fix race problems here. Signed-off-by: Wang Shilong <wshilong(a)ddn.com> Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d4a218ba626c..f7750bc5b85a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -795,26 +795,26 @@ void ext4_mark_group_bitmap_corrupted(struct super_block *sb, struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_group_info *grp = ext4_get_group_info(sb, group); struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL); + int ret; - if ((flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) && - !EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) { - percpu_counter_sub(&sbi->s_freeclusters_counter, - grp->bb_free); - set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, - &grp->bb_state); + if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) { + ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, + &grp->bb_state); + if (!ret) + percpu_counter_sub(&sbi->s_freeclusters_counter, + grp->bb_free); } - if ((flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) && - !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { - if (gdp) { + if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) { + ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, + &grp->bb_state); + if (!ret && gdp) { int count; count = ext4_free_inodes_count(sb, gdp); percpu_counter_sub(&sbi->s_freeinodes_counter, count); } - set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, - &grp->bb_state); } }

7 years, 2 months

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FAILED: patch "[PATCH] ext4: sysfs: print ext4_super_block fields as little-endian" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a4d2aadca184ece182418950d45ba4ffc7b652d2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd(a)arndb.de> Date: Sun, 29 Jul 2018 15:48:00 -0400 Subject: [PATCH] ext4: sysfs: print ext4_super_block fields as little-endian While working on extended rand for last_error/first_error timestamps, I noticed that the endianess is wrong; we access the little-endian fields in struct ext4_super_block as native-endian when we print them. This adds a special case in ext4_attr_show() and ext4_attr_store() to byteswap the superblock fields if needed. In older kernels, this code was part of super.c, it got moved to sysfs.c in linux-4.4. Cc: stable(a)vger.kernel.org Fixes: 52c198c6820f ("ext4: add sysfs entry showing whether the fs contains errors") Reviewed-by: Andreas Dilger <adilger(a)dilger.ca> Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index f34da0bb8f17..b970a200f20c 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -274,8 +274,12 @@ static ssize_t ext4_attr_show(struct kobject *kobj, case attr_pointer_ui: if (!ptr) return 0; - return snprintf(buf, PAGE_SIZE, "%u\n", - *((unsigned int *) ptr)); + if (a->attr_ptr == ptr_ext4_super_block_offset) + return snprintf(buf, PAGE_SIZE, "%u\n", + le32_to_cpup(ptr)); + else + return snprintf(buf, PAGE_SIZE, "%u\n", + *((unsigned int *) ptr)); case attr_pointer_atomic: if (!ptr) return 0; @@ -308,7 +312,10 @@ static ssize_t ext4_attr_store(struct kobject *kobj, ret = kstrtoul(skip_spaces(buf), 0, &t); if (ret) return ret; - *((unsigned int *) ptr) = t; + if (a->attr_ptr == ptr_ext4_super_block_offset) + *((__le32 *) ptr) = cpu_to_le32(t); + else + *((unsigned int *) ptr) = t; return len; case attr_inode_readahead: return inode_readahead_blks_store(sbi, buf, len);

7 years, 2 months

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FAILED: patch "[PATCH] KVM: arm/arm64: Skip updating PTE entry if no change" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 976d34e2dab10ece5ea8fe7090b7692913f89084 Mon Sep 17 00:00:00 2001 From: Punit Agrawal <punit.agrawal(a)arm.com> Date: Mon, 13 Aug 2018 11:43:51 +0100 Subject: [PATCH] KVM: arm/arm64: Skip updating PTE entry if no change When there is contention on faulting in a particular page table entry at stage 2, the break-before-make requirement of the architecture can lead to additional refaulting due to TLB invalidation. Avoid this by skipping a page table update if the new value of the PTE matches the previous value. Cc: stable(a)vger.kernel.org Fixes: d5d8184d35c9 ("KVM: ARM: Memory virtualization setup") Reviewed-by: Suzuki Poulose <suzuki.poulose(a)arm.com> Acked-by: Christoffer Dall <christoffer.dall(a)arm.com> Signed-off-by: Punit Agrawal <punit.agrawal(a)arm.com> Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 13dfe36501aa..91aaf73b00df 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1147,6 +1147,10 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, /* Create 2nd stage page table mapping - Level 3 */ old_pte = *pte; if (pte_present(old_pte)) { + /* Skip page table update if there is no change */ + if (pte_val(old_pte) == pte_val(*new_pte)) + return 0; + kvm_set_pte(pte, __pte(0)); kvm_tlb_flush_vmid_ipa(kvm, addr); } else {

7 years, 2 months

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FAILED: patch "[PATCH] KVM: arm/arm64: Skip updating PTE entry if no change" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 976d34e2dab10ece5ea8fe7090b7692913f89084 Mon Sep 17 00:00:00 2001 From: Punit Agrawal <punit.agrawal(a)arm.com> Date: Mon, 13 Aug 2018 11:43:51 +0100 Subject: [PATCH] KVM: arm/arm64: Skip updating PTE entry if no change When there is contention on faulting in a particular page table entry at stage 2, the break-before-make requirement of the architecture can lead to additional refaulting due to TLB invalidation. Avoid this by skipping a page table update if the new value of the PTE matches the previous value. Cc: stable(a)vger.kernel.org Fixes: d5d8184d35c9 ("KVM: ARM: Memory virtualization setup") Reviewed-by: Suzuki Poulose <suzuki.poulose(a)arm.com> Acked-by: Christoffer Dall <christoffer.dall(a)arm.com> Signed-off-by: Punit Agrawal <punit.agrawal(a)arm.com> Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 13dfe36501aa..91aaf73b00df 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1147,6 +1147,10 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, /* Create 2nd stage page table mapping - Level 3 */ old_pte = *pte; if (pte_present(old_pte)) { + /* Skip page table update if there is no change */ + if (pte_val(old_pte) == pte_val(*new_pte)) + return 0; + kvm_set_pte(pte, __pte(0)); kvm_tlb_flush_vmid_ipa(kvm, addr); } else {

7 years, 2 months

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FAILED: patch "[PATCH] KVM: arm/arm64: Skip updating PMD entry if no change" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 86658b819cd0a9aa584cd84453ed268a6f013770 Mon Sep 17 00:00:00 2001 From: Punit Agrawal <punit.agrawal(a)arm.com> Date: Mon, 13 Aug 2018 11:43:50 +0100 Subject: [PATCH] KVM: arm/arm64: Skip updating PMD entry if no change Contention on updating a PMD entry by a large number of vcpus can lead to duplicate work when handling stage 2 page faults. As the page table update follows the break-before-make requirement of the architecture, it can lead to repeated refaults due to clearing the entry and flushing the tlbs. This problem is more likely when - * there are large number of vcpus * the mapping is large block mapping such as when using PMD hugepages (512MB) with 64k pages. Fix this by skipping the page table update if there is no change in the entry being updated. Cc: stable(a)vger.kernel.org Fixes: ad361f093c1e ("KVM: ARM: Support hugetlbfs backed huge pages") Reviewed-by: Suzuki Poulose <suzuki.poulose(a)arm.com> Acked-by: Christoffer Dall <christoffer.dall(a)arm.com> Signed-off-by: Punit Agrawal <punit.agrawal(a)arm.com> Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 97d27cd9c654..13dfe36501aa 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1044,19 +1044,35 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache pmd = stage2_get_pmd(kvm, cache, addr); VM_BUG_ON(!pmd); - /* - * Mapping in huge pages should only happen through a fault. If a - * page is merged into a transparent huge page, the individual - * subpages of that huge page should be unmapped through MMU - * notifiers before we get here. - * - * Merging of CompoundPages is not supported; they should become - * splitting first, unmapped, merged, and mapped back in on-demand. - */ - VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd)); - old_pmd = *pmd; if (pmd_present(old_pmd)) { + /* + * Multiple vcpus faulting on the same PMD entry, can + * lead to them sequentially updating the PMD with the + * same value. Following the break-before-make + * (pmd_clear() followed by tlb_flush()) process can + * hinder forward progress due to refaults generated + * on missing translations. + * + * Skip updating the page table if the entry is + * unchanged. + */ + if (pmd_val(old_pmd) == pmd_val(*new_pmd)) + return 0; + + /* + * Mapping in huge pages should only happen through a + * fault. If a page is merged into a transparent huge + * page, the individual subpages of that huge page + * should be unmapped through MMU notifiers before we + * get here. + * + * Merging of CompoundPages is not supported; they + * should become splitting first, unmapped, merged, + * and mapped back in on-demand. + */ + VM_BUG_ON(pmd_pfn(old_pmd) != pmd_pfn(*new_pmd)); + pmd_clear(pmd); kvm_tlb_flush_vmid_ipa(kvm, addr); } else {

7 years, 2 months

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FAILED: patch "[PATCH] KVM: arm/arm64: Skip updating PMD entry if no change" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 86658b819cd0a9aa584cd84453ed268a6f013770 Mon Sep 17 00:00:00 2001 From: Punit Agrawal <punit.agrawal(a)arm.com> Date: Mon, 13 Aug 2018 11:43:50 +0100 Subject: [PATCH] KVM: arm/arm64: Skip updating PMD entry if no change Contention on updating a PMD entry by a large number of vcpus can lead to duplicate work when handling stage 2 page faults. As the page table update follows the break-before-make requirement of the architecture, it can lead to repeated refaults due to clearing the entry and flushing the tlbs. This problem is more likely when - * there are large number of vcpus * the mapping is large block mapping such as when using PMD hugepages (512MB) with 64k pages. Fix this by skipping the page table update if there is no change in the entry being updated. Cc: stable(a)vger.kernel.org Fixes: ad361f093c1e ("KVM: ARM: Support hugetlbfs backed huge pages") Reviewed-by: Suzuki Poulose <suzuki.poulose(a)arm.com> Acked-by: Christoffer Dall <christoffer.dall(a)arm.com> Signed-off-by: Punit Agrawal <punit.agrawal(a)arm.com> Signed-off-by: Marc Zyngier <marc.zyngier(a)arm.com> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 97d27cd9c654..13dfe36501aa 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1044,19 +1044,35 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache pmd = stage2_get_pmd(kvm, cache, addr); VM_BUG_ON(!pmd); - /* - * Mapping in huge pages should only happen through a fault. If a - * page is merged into a transparent huge page, the individual - * subpages of that huge page should be unmapped through MMU - * notifiers before we get here. - * - * Merging of CompoundPages is not supported; they should become - * splitting first, unmapped, merged, and mapped back in on-demand. - */ - VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd)); - old_pmd = *pmd; if (pmd_present(old_pmd)) { + /* + * Multiple vcpus faulting on the same PMD entry, can + * lead to them sequentially updating the PMD with the + * same value. Following the break-before-make + * (pmd_clear() followed by tlb_flush()) process can + * hinder forward progress due to refaults generated + * on missing translations. + * + * Skip updating the page table if the entry is + * unchanged. + */ + if (pmd_val(old_pmd) == pmd_val(*new_pmd)) + return 0; + + /* + * Mapping in huge pages should only happen through a + * fault. If a page is merged into a transparent huge + * page, the individual subpages of that huge page + * should be unmapped through MMU notifiers before we + * get here. + * + * Merging of CompoundPages is not supported; they + * should become splitting first, unmapped, merged, + * and mapped back in on-demand. + */ + VM_BUG_ON(pmd_pfn(old_pmd) != pmd_pfn(*new_pmd)); + pmd_clear(pmd); kvm_tlb_flush_vmid_ipa(kvm, addr); } else {

7 years, 2 months

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FAILED: patch "[PATCH] arm64: mm: check for upper PAGE_SHIFT bits in pfn_valid()" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5ad356eabc47d26a92140a0c4b20eba471c10de3 Mon Sep 17 00:00:00 2001 From: Greg Hackmann <ghackmann(a)android.com> Date: Wed, 15 Aug 2018 12:51:21 -0700 Subject: [PATCH] arm64: mm: check for upper PAGE_SHIFT bits in pfn_valid() ARM64's pfn_valid() shifts away the upper PAGE_SHIFT bits of the input before seeing if the PFN is valid. This leads to false positives when some of the upper bits are set, but the lower bits match a valid PFN. For example, the following userspace code looks up a bogus entry in /proc/kpageflags: int pagemap = open("/proc/self/pagemap", O_RDONLY); int pageflags = open("/proc/kpageflags", O_RDONLY); uint64_t pfn, val; lseek64(pagemap, [...], SEEK_SET); read(pagemap, &pfn, sizeof(pfn)); if (pfn & (1UL << 63)) { /* valid PFN */ pfn &= ((1UL << 55) - 1); /* clear flag bits */ pfn |= (1UL << 55); lseek64(pageflags, pfn * sizeof(uint64_t), SEEK_SET); read(pageflags, &val, sizeof(val)); } On ARM64 this causes the userspace process to crash with SIGSEGV rather than reading (1 << KPF_NOPAGE). kpageflags_read() treats the offset as valid, and stable_page_flags() will try to access an address between the user and kernel address ranges. Fixes: c1cc1552616d ("arm64: MMU initialisation") Cc: stable(a)vger.kernel.org Signed-off-by: Greg Hackmann <ghackmann(a)google.com> Signed-off-by: Will Deacon <will.deacon(a)arm.com> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 325cfb3b858a..811f9f8b3bb0 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -287,7 +287,11 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) #ifdef CONFIG_HAVE_ARCH_PFN_VALID int pfn_valid(unsigned long pfn) { - return memblock_is_map_memory(pfn << PAGE_SHIFT); + phys_addr_t addr = pfn << PAGE_SHIFT; + + if ((addr >> PAGE_SHIFT) != pfn) + return 0; + return memblock_is_map_memory(addr); } EXPORT_SYMBOL(pfn_valid); #endif

7 years, 2 months

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