- Linux-stable-mirror - lists.linaro.org

[PATCH 0/6] drm/panic: Fixes found with kunit.

by Jocelyn Falempe

A few fixes for drm panic, that I found when writing unit tests with kunit. Jocelyn Falempe (6): drm/panic: Fix drawing the logo on a small narrow screen drm/panic: Fix overlap between qr code and logo drm/panic: Fix qr_code, ensure vmargin is positive drm/panic: Fix kmsg text drawing rectangle drm/panic: Fix divide by 0 if the screen width < font width drm/panic: Fix 24bit pixel crossing page boundaries drivers/gpu/drm/drm_panic.c | 60 +++++++++++++++++++++++++++++++++---- 1 file changed, 54 insertions(+), 6 deletions(-) base-commit: e4bea919584ff292c9156cf7d641a2ab3cbe27b0 -- 2.51.0

3 weeks, 6 days

4
16
0 0

[PATCH] fs: Fix uninitialized 'offp' in statmount_string()

by Zhen Ni

In statmount_string(), most flags assign an output offset pointer (offp) which is later updated with the string offset. However, the STATMOUNT_MNT_UIDMAP and STATMOUNT_MNT_GIDMAP cases directly set the struct fields instead of using offp. This leaves offp uninitialized, leading to a possible uninitialized dereference when *offp is updated. Fix it by assigning offp for UIDMAP and GIDMAP as well, keeping the code path consistent. Fixes: 37c4a9590e1e ("statmount: allow to retrieve idmappings") Cc: stable(a)vger.kernel.org Signed-off-by: Zhen Ni <zhen.ni(a)easystack.cn> --- fs/namespace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index d82910f33dc4..5b5ab2ae238b 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -5454,11 +5454,11 @@ static int statmount_string(struct kstatmount *s, u64 flag) ret = statmount_sb_source(s, seq); break; case STATMOUNT_MNT_UIDMAP: - sm->mnt_uidmap = start; + offp = &sm->mnt_uidmap; ret = statmount_mnt_uidmap(s, seq); break; case STATMOUNT_MNT_GIDMAP: - sm->mnt_gidmap = start; + offp = &sm->mnt_gidmap; ret = statmount_mnt_gidmap(s, seq); break; default: -- 2.20.1

3 weeks, 6 days

3
3
0 0

[PATCH 6.12.y] mm/ksm: fix flag-dropping behavior in ksm_madvise

by Jakub Acs

[ Upstream commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 ] syzkaller discovered the following crash: (kernel BUG) [ 44.607039] ------------[ cut here ]------------ [ 44.607422] kernel BUG at mm/userfaultfd.c:2067! [ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none) [ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460 <snip other registers, drop unreliable trace> [ 44.617726] Call Trace: [ 44.617926] <TASK> [ 44.619284] userfaultfd_release+0xef/0x1b0 [ 44.620976] __fput+0x3f9/0xb60 [ 44.621240] fput_close_sync+0x110/0x210 [ 44.622222] __x64_sys_close+0x8f/0x120 [ 44.622530] do_syscall_64+0x5b/0x2f0 [ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 44.623244] RIP: 0033:0x7f365bb3f227 Kernel panics because it detects UFFD inconsistency during userfaultfd_release_all(). Specifically, a VMA which has a valid pointer to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags. The inconsistency is caused in ksm_madvise(): when user calls madvise() with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode, it accidentally clears all flags stored in the upper 32 bits of vma->vm_flags. Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and int are 32-bit wide. This setup causes the following mishap during the &= ~VM_MERGEABLE assignment. VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then promoted to unsigned long before the & operation. This promotion fills upper 32 bits with leading 0s, as we're doing unsigned conversion (and even for a signed conversion, this wouldn't help as the leading bit is 0). & operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears the upper 32-bits of its value. Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the BIT() macro. Note: other VM_* flags are not affected: This only happens to the VM_MERGEABLE flag, as the other VM_* flags are all constants of type int and after ~ operation, they end up with leading 1 and are thus converted to unsigned long with leading 1s. Note 2: After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is no longer a kernel BUG, but a WARNING at the same place: [ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067 but the root-cause (flag-drop) remains the same. [akpm(a)linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel] Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/ Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode") Signed-off-by: Jakub Acs <acsjakub(a)amazon.de> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Acked-by: SeongJae Park <sj(a)kernel.org> Tested-by: Alice Ryhl <aliceryhl(a)google.com> Tested-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Cc: Xu Xin <xu.xin16(a)zte.com.cn> Cc: Chengming Zhou <chengming.zhou(a)linux.dev> Cc: Peter Xu <peterx(a)redhat.com> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> [acsjakub(a)amazon.de: adjust context in bindgings_helper.h] Signed-off-by: Jakub Acs <acsjakub(a)amazon.de> --- Tested that CONFIG_RUST=y builds with LLVM=1 with toolchain from https://mirrors.edge.kernel.org/pub/tools/llvm/rust/. include/linux/mm.h | 2 +- rust/bindings/bindings_helper.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index f0fa8404957d..13b4bd7355c1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -320,7 +320,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ #define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */ #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ -#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */ +#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */ #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS #define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */ diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index a80783fcbe04..8b97919a86e2 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -33,3 +33,4 @@ const gfp_t RUST_CONST_HELPER___GFP_ZERO = __GFP_ZERO; const gfp_t RUST_CONST_HELPER___GFP_HIGHMEM = ___GFP_HIGHMEM; const gfp_t RUST_CONST_HELPER___GFP_NOWARN = ___GFP_NOWARN; const blk_features_t RUST_CONST_HELPER_BLK_FEAT_ROTATIONAL = BLK_FEAT_ROTATIONAL; +const vm_flags_t RUST_CONST_HELPER_VM_MERGEABLE = VM_MERGEABLE; -- 2.47.3 Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

3 weeks, 6 days

1
0
0 0

[PATCH 6.6.y] mm/ksm: fix flag-dropping behavior in ksm_madvise

by Jakub Acs

[ Upstream commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 ] syzkaller discovered the following crash: (kernel BUG) [ 44.607039] ------------[ cut here ]------------ [ 44.607422] kernel BUG at mm/userfaultfd.c:2067! [ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none) [ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460 <snip other registers, drop unreliable trace> [ 44.617726] Call Trace: [ 44.617926] <TASK> [ 44.619284] userfaultfd_release+0xef/0x1b0 [ 44.620976] __fput+0x3f9/0xb60 [ 44.621240] fput_close_sync+0x110/0x210 [ 44.622222] __x64_sys_close+0x8f/0x120 [ 44.622530] do_syscall_64+0x5b/0x2f0 [ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 44.623244] RIP: 0033:0x7f365bb3f227 Kernel panics because it detects UFFD inconsistency during userfaultfd_release_all(). Specifically, a VMA which has a valid pointer to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags. The inconsistency is caused in ksm_madvise(): when user calls madvise() with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode, it accidentally clears all flags stored in the upper 32 bits of vma->vm_flags. Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and int are 32-bit wide. This setup causes the following mishap during the &= ~VM_MERGEABLE assignment. VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then promoted to unsigned long before the & operation. This promotion fills upper 32 bits with leading 0s, as we're doing unsigned conversion (and even for a signed conversion, this wouldn't help as the leading bit is 0). & operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears the upper 32-bits of its value. Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the BIT() macro. Note: other VM_* flags are not affected: This only happens to the VM_MERGEABLE flag, as the other VM_* flags are all constants of type int and after ~ operation, they end up with leading 1 and are thus converted to unsigned long with leading 1s. Note 2: After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is no longer a kernel BUG, but a WARNING at the same place: [ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067 but the root-cause (flag-drop) remains the same. [akpm(a)linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel] Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/ Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode") Signed-off-by: Jakub Acs <acsjakub(a)amazon.de> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Acked-by: SeongJae Park <sj(a)kernel.org> Tested-by: Alice Ryhl <aliceryhl(a)google.com> Tested-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Cc: Xu Xin <xu.xin16(a)zte.com.cn> Cc: Chengming Zhou <chengming.zhou(a)linux.dev> Cc: Peter Xu <peterx(a)redhat.com> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> [acsjakub(a)amazon.de: adapt rust bindgen const to older versions] Signed-off-by: Jakub Acs <acsjakub(a)amazon.de> --- I inferred the rust adaptation from the neighboring definitions. Could rust folks please also check that it makes sense? Tested that CONFIG_RUST=y builds with LLVM=1 with toolchain from https://mirrors.edge.kernel.org/pub/tools/llvm/rust/. include/linux/mm.h | 2 +- rust/bindings/bindings_helper.h | 2 ++ rust/bindings/lib.rs | 1 + 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index ba77f08900ca..fa5b11452ae6 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -315,7 +315,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ #define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */ #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ -#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */ +#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */ #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS #define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */ diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index c91a3c24f607..5416f21918e0 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -12,8 +12,10 @@ #include <linux/refcount.h> #include <linux/wait.h> #include <linux/sched.h> +#include <linux/mm.h> /* `bindgen` gets confused at certain things. */ const size_t BINDINGS_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN; const gfp_t BINDINGS_GFP_KERNEL = GFP_KERNEL; const gfp_t BINDINGS___GFP_ZERO = __GFP_ZERO; +const vm_flags_t BINDINGS_VM_MERGEABLE = VM_MERGEABLE; diff --git a/rust/bindings/lib.rs b/rust/bindings/lib.rs index 9bcbea04dac3..7d9078b94a8f 100644 --- a/rust/bindings/lib.rs +++ b/rust/bindings/lib.rs @@ -51,3 +51,4 @@ mod bindings_helper { pub const GFP_KERNEL: gfp_t = BINDINGS_GFP_KERNEL; pub const __GFP_ZERO: gfp_t = BINDINGS___GFP_ZERO; +pub const VM_MERGEABLE: vm_flags_t = BINDINGS_VM_MERGEABLE; -- 2.47.3 Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

3 weeks, 6 days

1
0
0 0

[PATCH 6.1.y] mm/ksm: fix flag-dropping behavior in ksm_madvise

by Jakub Acs

[ Upstream commit f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 ] syzkaller discovered the following crash: (kernel BUG) [ 44.607039] ------------[ cut here ]------------ [ 44.607422] kernel BUG at mm/userfaultfd.c:2067! [ 44.608148] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI [ 44.608814] CPU: 1 UID: 0 PID: 2475 Comm: reproducer Not tainted 6.16.0-rc6 #1 PREEMPT(none) [ 44.609635] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 44.610695] RIP: 0010:userfaultfd_release_all+0x3a8/0x460 <snip other registers, drop unreliable trace> [ 44.617726] Call Trace: [ 44.617926] <TASK> [ 44.619284] userfaultfd_release+0xef/0x1b0 [ 44.620976] __fput+0x3f9/0xb60 [ 44.621240] fput_close_sync+0x110/0x210 [ 44.622222] __x64_sys_close+0x8f/0x120 [ 44.622530] do_syscall_64+0x5b/0x2f0 [ 44.622840] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 44.623244] RIP: 0033:0x7f365bb3f227 Kernel panics because it detects UFFD inconsistency during userfaultfd_release_all(). Specifically, a VMA which has a valid pointer to vma->vm_userfaultfd_ctx, but no UFFD flags in vma->vm_flags. The inconsistency is caused in ksm_madvise(): when user calls madvise() with MADV_UNMEARGEABLE on a VMA that is registered for UFFD in MINOR mode, it accidentally clears all flags stored in the upper 32 bits of vma->vm_flags. Assuming x86_64 kernel build, unsigned long is 64-bit and unsigned int and int are 32-bit wide. This setup causes the following mishap during the &= ~VM_MERGEABLE assignment. VM_MERGEABLE is a 32-bit constant of type unsigned int, 0x8000'0000. After ~ is applied, it becomes 0x7fff'ffff unsigned int, which is then promoted to unsigned long before the & operation. This promotion fills upper 32 bits with leading 0s, as we're doing unsigned conversion (and even for a signed conversion, this wouldn't help as the leading bit is 0). & operation thus ends up AND-ing vm_flags with 0x0000'0000'7fff'ffff instead of intended 0xffff'ffff'7fff'ffff and hence accidentally clears the upper 32-bits of its value. Fix it by changing `VM_MERGEABLE` constant to unsigned long, using the BIT() macro. Note: other VM_* flags are not affected: This only happens to the VM_MERGEABLE flag, as the other VM_* flags are all constants of type int and after ~ operation, they end up with leading 1 and are thus converted to unsigned long with leading 1s. Note 2: After commit 31defc3b01d9 ("userfaultfd: remove (VM_)BUG_ON()s"), this is no longer a kernel BUG, but a WARNING at the same place: [ 45.595973] WARNING: CPU: 1 PID: 2474 at mm/userfaultfd.c:2067 but the root-cause (flag-drop) remains the same. [akpm(a)linux-foundation.org: rust bindgen wasn't able to handle BIT(), from Miguel] Link: https://lore.kernel.org/oe-kbuild-all/202510030449.VfSaAjvd-lkp@intel.com/ Link: https://lkml.kernel.org/r/20251001090353.57523-2-acsjakub@amazon.de Fixes: 7677f7fd8be7 ("userfaultfd: add minor fault registration mode") Signed-off-by: Jakub Acs <acsjakub(a)amazon.de> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Acked-by: David Hildenbrand <david(a)redhat.com> Acked-by: SeongJae Park <sj(a)kernel.org> Tested-by: Alice Ryhl <aliceryhl(a)google.com> Tested-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Cc: Xu Xin <xu.xin16(a)zte.com.cn> Cc: Chengming Zhou <chengming.zhou(a)linux.dev> Cc: Peter Xu <peterx(a)redhat.com> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> [acsjakub(a)amazon.de: adapt rust bindgen to older versions] Signed-off-by: Jakub Acs <acsjakub(a)amazon.de> --- I inferred the rust adaptation from the neighboring definitions. Could rust folks please also check that it makes sense? Tested that CONFIG_RUST=y builds with LLVM=1 with toolchain from https://mirrors.edge.kernel.org/pub/tools/llvm/rust/ (used bindgen 0.56.0 from github, as it's no longer available at crates.io) include/linux/mm.h | 2 +- rust/bindings/bindings_helper.h | 2 ++ rust/bindings/lib.rs | 1 + 3 files changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 3bf7823e1097..44381ffaf34b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -316,7 +316,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ #define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */ #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ -#define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */ +#define VM_MERGEABLE BIT(31) /* KSM may merge identical pages */ #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS #define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */ diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index fdb4e11df3bd..2f5fd797955a 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -7,8 +7,10 @@ */ #include <linux/slab.h> +#include <linux/mm.h> /* `bindgen` gets confused at certain things. */ const size_t BINDINGS_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN; const gfp_t BINDINGS_GFP_KERNEL = GFP_KERNEL; const gfp_t BINDINGS___GFP_ZERO = __GFP_ZERO; +const vm_flags_t BINDINGS_VM_MERGEABLE = VM_MERGEABLE; diff --git a/rust/bindings/lib.rs b/rust/bindings/lib.rs index 6c50ee62c56b..8cf84e899817 100644 --- a/rust/bindings/lib.rs +++ b/rust/bindings/lib.rs @@ -51,3 +51,4 @@ pub use bindings_raw::*; pub const GFP_KERNEL: gfp_t = BINDINGS_GFP_KERNEL; pub const __GFP_ZERO: gfp_t = BINDINGS___GFP_ZERO; +pub const VM_MERGEABLE: vm_flags_t = BINDINGS_VM_MERGEABLE; -- 2.47.3 Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

3 weeks, 6 days

1
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[tip: locking/core] locking/spinlock/debug: Fix data-race in do_raw_write_lock

by tip-bot2 for Alexander Sverdlin

The following commit has been merged into the locking/core branch of tip: Commit-ID: c14ecb555c3ee80eeb030a4e46d00e679537f03a Gitweb: https://git.kernel.org/tip/c14ecb555c3ee80eeb030a4e46d00e679537f03a Author: Alexander Sverdlin <alexander.sverdlin(a)siemens.com> AuthorDate: Fri, 19 Sep 2025 11:12:38 +02:00 Committer: Peter Zijlstra <peterz(a)infradead.org> CommitterDate: Tue, 21 Oct 2025 12:31:55 +02:00 locking/spinlock/debug: Fix data-race in do_raw_write_lock KCSAN reports: BUG: KCSAN: data-race in do_raw_write_lock / do_raw_write_lock write (marked) to 0xffff800009cf504c of 4 bytes by task 1102 on cpu 1: do_raw_write_lock+0x120/0x204 _raw_write_lock_irq do_exit call_usermodehelper_exec_async ret_from_fork read to 0xffff800009cf504c of 4 bytes by task 1103 on cpu 0: do_raw_write_lock+0x88/0x204 _raw_write_lock_irq do_exit call_usermodehelper_exec_async ret_from_fork value changed: 0xffffffff -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 1103 Comm: kworker/u4:1 6.1.111 Commit 1a365e822372 ("locking/spinlock/debug: Fix various data races") has adressed most of these races, but seems to be not consistent/not complete. >From do_raw_write_lock() only debug_write_lock_after() part has been converted to WRITE_ONCE(), but not debug_write_lock_before() part. Do it now. Fixes: 1a365e822372 ("locking/spinlock/debug: Fix various data races") Reported-by: Adrian Freihofer <adrian.freihofer(a)siemens.com> Signed-off-by: Alexander Sverdlin <alexander.sverdlin(a)siemens.com> Signed-off-by: Boqun Feng <boqun.feng(a)gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Reviewed-by: Paul E. McKenney <paulmck(a)kernel.org> Acked-by: Waiman Long <longman(a)redhat.com> Cc: stable(a)vger.kernel.org --- kernel/locking/spinlock_debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/locking/spinlock_debug.c b/kernel/locking/spinlock_debug.c index 87b03d2..2338b3a 100644 --- a/kernel/locking/spinlock_debug.c +++ b/kernel/locking/spinlock_debug.c @@ -184,8 +184,8 @@ void do_raw_read_unlock(rwlock_t *lock) static inline void debug_write_lock_before(rwlock_t *lock) { RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); - RWLOCK_BUG_ON(lock->owner == current, lock, "recursion"); - RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), + RWLOCK_BUG_ON(READ_ONCE(lock->owner) == current, lock, "recursion"); + RWLOCK_BUG_ON(READ_ONCE(lock->owner_cpu) == raw_smp_processor_id(), lock, "cpu recursion"); }

3 weeks, 6 days

1
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[PATCH 6.1 0/8] Backporting CVE-2025-38073 fix patch

by Mahmoud Adam

This series aims to fix the CVE-2025-38073 for 6.1 LTS. Which is fixed by c0e473a0d226 ("block: fix race between set_blocksize and read paths"). This patch is built on top multiple refactors that where merged on 6.6. The needed dependecies are: - e003f74afbd2 ("filemap: add a kiocb_invalidate_pages helper") - c402a9a9430b ("filemap: add a kiocb_invalidate_post_direct_write helper") - 182c25e9c157 ("filemap: update ki_pos in generic_perform_write") - 44fff0fa08ec ("fs: factor out a direct_write_fallback helper") - 727cfe976758 ("block: open code __generic_file_write_iter for blkdev writes") Also backport follow up fixes: - fb881cd76045 ("nilfs2: fix deadlock warnings caused by lock dependency in init_nilfs()"). - 8287474aa5ff ("direct_write_fallback(): on error revert the ->ki_pos update from buffered write") Thanks, MNAdam Al Viro (1): direct_write_fallback(): on error revert the ->ki_pos update from buffered write Christoph Hellwig (5): filemap: add a kiocb_invalidate_pages helper filemap: add a kiocb_invalidate_post_direct_write helper filemap: update ki_pos in generic_perform_write fs: factor out a direct_write_fallback helper block: open code __generic_file_write_iter for blkdev writes Darrick J. Wong (1): block: fix race between set_blocksize and read paths Ryusuke Konishi (1): nilfs2: fix deadlock warnings caused by lock dependency in init_nilfs() block/bdev.c | 17 +++++ block/blk-zoned.c | 5 +- block/fops.c | 61 +++++++++++++++- block/ioctl.c | 6 ++ fs/ceph/file.c | 2 - fs/direct-io.c | 10 +-- fs/ext4/file.c | 9 +-- fs/f2fs/file.c | 1 - fs/iomap/direct-io.c | 12 +--- fs/libfs.c | 42 +++++++++++ fs/nfs/file.c | 1 - fs/nilfs2/the_nilfs.c | 3 - include/linux/fs.h | 7 +- include/linux/pagemap.h | 2 + mm/filemap.c | 154 +++++++++++++++++----------------------- 15 files changed, 205 insertions(+), 127 deletions(-) -- 2.47.3 Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

3 weeks, 6 days

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[PATCH v1 2/2] powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages

by David Hildenbrand

Let's properly adjust BALLOON_MIGRATE like the other drivers. Note that the INFLATE/DEFLATE events are triggered from the core when enqueueing/dequeueing pages. Not completely sure whether really is stable material, but the fix is trivial so let's just CC stable. This was found by code inspection. Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction") Cc: <stable(a)vger.kernel.org> Signed-off-by: David Hildenbrand <david(a)redhat.com> --- arch/powerpc/platforms/pseries/cmm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 688f5fa1c7245..310dab4bc8679 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -532,6 +532,7 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info, spin_lock_irqsave(&b_dev_info->pages_lock, flags); balloon_page_insert(b_dev_info, newpage); + __count_vm_event(BALLOON_MIGRATE); b_dev_info->isolated_pages--; spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); -- 2.51.0

3 weeks, 6 days

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[PATCH v1 1/2] powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION

by David Hildenbrand

We always have to initialize the balloon_dev_info, even when compaction is not configured in: otherwise the containing list and the lock are left uninitialized. Likely not many such configs exist in practice, but let's CC stable to be sure. This was found by code inspection. Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction") Cc: <stable(a)vger.kernel.org> Signed-off-by: David Hildenbrand <david(a)redhat.com> --- arch/powerpc/platforms/pseries/cmm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 0823fa2da1516..688f5fa1c7245 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -550,7 +550,6 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info, static void cmm_balloon_compaction_init(void) { - balloon_devinfo_init(&b_dev_info); b_dev_info.migratepage = cmm_migratepage; } #else /* CONFIG_BALLOON_COMPACTION */ @@ -572,6 +571,7 @@ static int cmm_init(void) if (!firmware_has_feature(FW_FEATURE_CMO) && !simulate) return -EOPNOTSUPP; + balloon_devinfo_init(&b_dev_info); cmm_balloon_compaction_init(); rc = register_oom_notifier(&cmm_oom_nb); -- 2.51.0

3 weeks, 6 days

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[PATCH] rtc: amlogic-a4: fix double free caused by devm

by Haotian Zhang

The clock obtained via devm_clk_get_enabled() is automatically managed by devres and will be disabled and freed on driver detach. Manually calling clk_disable_unprepare() in error path and remove function causes double free. Remove the redundant clk_disable_unprepare() calls from the probe error path and aml_rtc_remove(), allowing the devm framework to automatically manage the clock lifecycle. Fixes: c89ac9182ee2 ("rtc: support for the Amlogic on-chip RTC") Signed-off-by: Haotian Zhang <vulab(a)iscas.ac.cn> --- drivers/rtc/rtc-amlogic-a4.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/rtc/rtc-amlogic-a4.c b/drivers/rtc/rtc-amlogic-a4.c index 1928b29c1045..ed36b649c057 100644 --- a/drivers/rtc/rtc-amlogic-a4.c +++ b/drivers/rtc/rtc-amlogic-a4.c @@ -390,7 +390,6 @@ static int aml_rtc_probe(struct platform_device *pdev) return 0; err_clk: - clk_disable_unprepare(rtc->sys_clk); device_init_wakeup(dev, false); return ret; @@ -425,7 +424,6 @@ static void aml_rtc_remove(struct platform_device *pdev) { struct aml_rtc_data *rtc = dev_get_drvdata(&pdev->dev); - clk_disable_unprepare(rtc->sys_clk); device_init_wakeup(&pdev->dev, false); } -- 2.25.1

3 weeks, 6 days

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