January 2023 - Linux-stable-mirror

FAILED: patch "[PATCH] arm64: cmpxchg_double*: hazard against entire exchange" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-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>. Possible dependencies: 031af50045ea ("arm64: cmpxchg_double*: hazard against entire exchange variable") b2c3ccbd0011 ("arm64: atomics: remove LL/SC trampolines") 8e6082e94aac ("arm64: atomics: format whitespace consistently") 4f6cdf296cc4 ("Merge branches 'for-next/acpi', 'for-next/cpufeatures', 'for-next/csum', 'for-next/e0pd', 'for-next/entry', 'for-next/kbuild', 'for-next/kexec/cleanup', 'for-next/kexec/file-kdump', 'for-next/misc', 'for-next/nofpsimd', 'for-next/perf' and 'for-next/scs' into for-next/core") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 031af50045ea97ed4386eb3751ca2c134d0fc911 Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland(a)arm.com> Date: Wed, 4 Jan 2023 15:16:26 +0000 Subject: [PATCH] arm64: cmpxchg_double*: hazard against entire exchange variable The inline assembly for arm64's cmpxchg_double*() implementations use a +Q constraint to hazard against other accesses to the memory location being exchanged. However, the pointer passed to the constraint is a pointer to unsigned long, and thus the hazard only applies to the first 8 bytes of the location. GCC can take advantage of this, assuming that other portions of the location are unchanged, leading to a number of potential problems. This is similar to what we fixed back in commit: fee960bed5e857eb ("arm64: xchg: hazard against entire exchange variable") ... but we forgot to adjust cmpxchg_double*() similarly at the same time. The same problem applies, as demonstrated with the following test: | struct big { | u64 lo, hi; | } __aligned(128); | | unsigned long foo(struct big *b) | { | u64 hi_old, hi_new; | | hi_old = b->hi; | cmpxchg_double_local(&b->lo, &b->hi, 0x12, 0x34, 0x56, 0x78); | hi_new = b->hi; | | return hi_old ^ hi_new; | } ... which GCC 12.1.0 compiles as: | 0000000000000000 <foo>: | 0: d503233f paciasp | 4: aa0003e4 mov x4, x0 | 8: 1400000e b 40 <foo+0x40> | c: d2800240 mov x0, #0x12 // #18 | 10: d2800681 mov x1, #0x34 // #52 | 14: aa0003e5 mov x5, x0 | 18: aa0103e6 mov x6, x1 | 1c: d2800ac2 mov x2, #0x56 // #86 | 20: d2800f03 mov x3, #0x78 // #120 | 24: 48207c82 casp x0, x1, x2, x3, [x4] | 28: ca050000 eor x0, x0, x5 | 2c: ca060021 eor x1, x1, x6 | 30: aa010000 orr x0, x0, x1 | 34: d2800000 mov x0, #0x0 // #0 <--- BANG | 38: d50323bf autiasp | 3c: d65f03c0 ret | 40: d2800240 mov x0, #0x12 // #18 | 44: d2800681 mov x1, #0x34 // #52 | 48: d2800ac2 mov x2, #0x56 // #86 | 4c: d2800f03 mov x3, #0x78 // #120 | 50: f9800091 prfm pstl1strm, [x4] | 54: c87f1885 ldxp x5, x6, [x4] | 58: ca0000a5 eor x5, x5, x0 | 5c: ca0100c6 eor x6, x6, x1 | 60: aa0600a6 orr x6, x5, x6 | 64: b5000066 cbnz x6, 70 <foo+0x70> | 68: c8250c82 stxp w5, x2, x3, [x4] | 6c: 35ffff45 cbnz w5, 54 <foo+0x54> | 70: d2800000 mov x0, #0x0 // #0 <--- BANG | 74: d50323bf autiasp | 78: d65f03c0 ret Notice that at the lines with "BANG" comments, GCC has assumed that the higher 8 bytes are unchanged by the cmpxchg_double() call, and that `hi_old ^ hi_new` can be reduced to a constant zero, for both LSE and LL/SC versions of cmpxchg_double(). This patch fixes the issue by passing a pointer to __uint128_t into the +Q constraint, ensuring that the compiler hazards against the entire 16 bytes being modified. With this change, GCC 12.1.0 compiles the above test as: | 0000000000000000 <foo>: | 0: f9400407 ldr x7, [x0, #8] | 4: d503233f paciasp | 8: aa0003e4 mov x4, x0 | c: 1400000f b 48 <foo+0x48> | 10: d2800240 mov x0, #0x12 // #18 | 14: d2800681 mov x1, #0x34 // #52 | 18: aa0003e5 mov x5, x0 | 1c: aa0103e6 mov x6, x1 | 20: d2800ac2 mov x2, #0x56 // #86 | 24: d2800f03 mov x3, #0x78 // #120 | 28: 48207c82 casp x0, x1, x2, x3, [x4] | 2c: ca050000 eor x0, x0, x5 | 30: ca060021 eor x1, x1, x6 | 34: aa010000 orr x0, x0, x1 | 38: f9400480 ldr x0, [x4, #8] | 3c: d50323bf autiasp | 40: ca0000e0 eor x0, x7, x0 | 44: d65f03c0 ret | 48: d2800240 mov x0, #0x12 // #18 | 4c: d2800681 mov x1, #0x34 // #52 | 50: d2800ac2 mov x2, #0x56 // #86 | 54: d2800f03 mov x3, #0x78 // #120 | 58: f9800091 prfm pstl1strm, [x4] | 5c: c87f1885 ldxp x5, x6, [x4] | 60: ca0000a5 eor x5, x5, x0 | 64: ca0100c6 eor x6, x6, x1 | 68: aa0600a6 orr x6, x5, x6 | 6c: b5000066 cbnz x6, 78 <foo+0x78> | 70: c8250c82 stxp w5, x2, x3, [x4] | 74: 35ffff45 cbnz w5, 5c <foo+0x5c> | 78: f9400480 ldr x0, [x4, #8] | 7c: d50323bf autiasp | 80: ca0000e0 eor x0, x7, x0 | 84: d65f03c0 ret ... sampling the high 8 bytes before and after the cmpxchg, and performing an EOR, as we'd expect. For backporting, I've tested this atop linux-4.9.y with GCC 5.5.0. Note that linux-4.9.y is oldest currently supported stable release, and mandates GCC 5.1+. Unfortunately I couldn't get a GCC 5.1 binary to run on my machines due to library incompatibilities. I've also used a standalone test to check that we can use a __uint128_t pointer in a +Q constraint at least as far back as GCC 4.8.5 and LLVM 3.9.1. Fixes: 5284e1b4bc8a ("arm64: xchg: Implement cmpxchg_double") Fixes: e9a4b795652f ("arm64: cmpxchg_dbl: patch in lse instructions when supported by the CPU") Reported-by: Boqun Feng <boqun.feng(a)gmail.com> Link: https://lore.kernel.org/lkml/Y6DEfQXymYVgL3oJ@boqun-archlinux/ Reported-by: Peter Zijlstra <peterz(a)infradead.org> Link: https://lore.kernel.org/lkml/Y6GXoO4qmH9OIZ5Q@hirez.programming.kicks-ass.n… Signed-off-by: Mark Rutland <mark.rutland(a)arm.com> Cc: stable(a)vger.kernel.org Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Steve Capper <steve.capper(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Link: https://lore.kernel.org/r/20230104151626.3262137-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will(a)kernel.org> diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h index 0890e4f568fb..cbb3d961123b 100644 --- a/arch/arm64/include/asm/atomic_ll_sc.h +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -315,7 +315,7 @@ __ll_sc__cmpxchg_double##name(unsigned long old1, \ " cbnz %w0, 1b\n" \ " " #mb "\n" \ "2:" \ - : "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \ + : "=&r" (tmp), "=&r" (ret), "+Q" (*(__uint128_t *)ptr) \ : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \ : cl); \ \ diff --git a/arch/arm64/include/asm/atomic_lse.h b/arch/arm64/include/asm/atomic_lse.h index 52075e93de6c..a94d6dacc029 100644 --- a/arch/arm64/include/asm/atomic_lse.h +++ b/arch/arm64/include/asm/atomic_lse.h @@ -311,7 +311,7 @@ __lse__cmpxchg_double##name(unsigned long old1, \ " eor %[old2], %[old2], %[oldval2]\n" \ " orr %[old1], %[old1], %[old2]" \ : [old1] "+&r" (x0), [old2] "+&r" (x1), \ - [v] "+Q" (*(unsigned long *)ptr) \ + [v] "+Q" (*(__uint128_t *)ptr) \ : [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \ [oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \ : cl); \

2 years, 1 month

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FAILED: patch "[PATCH] arm64: cmpxchg_double*: hazard against entire exchange" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-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>. Possible dependencies: 031af50045ea ("arm64: cmpxchg_double*: hazard against entire exchange variable") b2c3ccbd0011 ("arm64: atomics: remove LL/SC trampolines") 8e6082e94aac ("arm64: atomics: format whitespace consistently") 4f6cdf296cc4 ("Merge branches 'for-next/acpi', 'for-next/cpufeatures', 'for-next/csum', 'for-next/e0pd', 'for-next/entry', 'for-next/kbuild', 'for-next/kexec/cleanup', 'for-next/kexec/file-kdump', 'for-next/misc', 'for-next/nofpsimd', 'for-next/perf' and 'for-next/scs' into for-next/core") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 031af50045ea97ed4386eb3751ca2c134d0fc911 Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland(a)arm.com> Date: Wed, 4 Jan 2023 15:16:26 +0000 Subject: [PATCH] arm64: cmpxchg_double*: hazard against entire exchange variable The inline assembly for arm64's cmpxchg_double*() implementations use a +Q constraint to hazard against other accesses to the memory location being exchanged. However, the pointer passed to the constraint is a pointer to unsigned long, and thus the hazard only applies to the first 8 bytes of the location. GCC can take advantage of this, assuming that other portions of the location are unchanged, leading to a number of potential problems. This is similar to what we fixed back in commit: fee960bed5e857eb ("arm64: xchg: hazard against entire exchange variable") ... but we forgot to adjust cmpxchg_double*() similarly at the same time. The same problem applies, as demonstrated with the following test: | struct big { | u64 lo, hi; | } __aligned(128); | | unsigned long foo(struct big *b) | { | u64 hi_old, hi_new; | | hi_old = b->hi; | cmpxchg_double_local(&b->lo, &b->hi, 0x12, 0x34, 0x56, 0x78); | hi_new = b->hi; | | return hi_old ^ hi_new; | } ... which GCC 12.1.0 compiles as: | 0000000000000000 <foo>: | 0: d503233f paciasp | 4: aa0003e4 mov x4, x0 | 8: 1400000e b 40 <foo+0x40> | c: d2800240 mov x0, #0x12 // #18 | 10: d2800681 mov x1, #0x34 // #52 | 14: aa0003e5 mov x5, x0 | 18: aa0103e6 mov x6, x1 | 1c: d2800ac2 mov x2, #0x56 // #86 | 20: d2800f03 mov x3, #0x78 // #120 | 24: 48207c82 casp x0, x1, x2, x3, [x4] | 28: ca050000 eor x0, x0, x5 | 2c: ca060021 eor x1, x1, x6 | 30: aa010000 orr x0, x0, x1 | 34: d2800000 mov x0, #0x0 // #0 <--- BANG | 38: d50323bf autiasp | 3c: d65f03c0 ret | 40: d2800240 mov x0, #0x12 // #18 | 44: d2800681 mov x1, #0x34 // #52 | 48: d2800ac2 mov x2, #0x56 // #86 | 4c: d2800f03 mov x3, #0x78 // #120 | 50: f9800091 prfm pstl1strm, [x4] | 54: c87f1885 ldxp x5, x6, [x4] | 58: ca0000a5 eor x5, x5, x0 | 5c: ca0100c6 eor x6, x6, x1 | 60: aa0600a6 orr x6, x5, x6 | 64: b5000066 cbnz x6, 70 <foo+0x70> | 68: c8250c82 stxp w5, x2, x3, [x4] | 6c: 35ffff45 cbnz w5, 54 <foo+0x54> | 70: d2800000 mov x0, #0x0 // #0 <--- BANG | 74: d50323bf autiasp | 78: d65f03c0 ret Notice that at the lines with "BANG" comments, GCC has assumed that the higher 8 bytes are unchanged by the cmpxchg_double() call, and that `hi_old ^ hi_new` can be reduced to a constant zero, for both LSE and LL/SC versions of cmpxchg_double(). This patch fixes the issue by passing a pointer to __uint128_t into the +Q constraint, ensuring that the compiler hazards against the entire 16 bytes being modified. With this change, GCC 12.1.0 compiles the above test as: | 0000000000000000 <foo>: | 0: f9400407 ldr x7, [x0, #8] | 4: d503233f paciasp | 8: aa0003e4 mov x4, x0 | c: 1400000f b 48 <foo+0x48> | 10: d2800240 mov x0, #0x12 // #18 | 14: d2800681 mov x1, #0x34 // #52 | 18: aa0003e5 mov x5, x0 | 1c: aa0103e6 mov x6, x1 | 20: d2800ac2 mov x2, #0x56 // #86 | 24: d2800f03 mov x3, #0x78 // #120 | 28: 48207c82 casp x0, x1, x2, x3, [x4] | 2c: ca050000 eor x0, x0, x5 | 30: ca060021 eor x1, x1, x6 | 34: aa010000 orr x0, x0, x1 | 38: f9400480 ldr x0, [x4, #8] | 3c: d50323bf autiasp | 40: ca0000e0 eor x0, x7, x0 | 44: d65f03c0 ret | 48: d2800240 mov x0, #0x12 // #18 | 4c: d2800681 mov x1, #0x34 // #52 | 50: d2800ac2 mov x2, #0x56 // #86 | 54: d2800f03 mov x3, #0x78 // #120 | 58: f9800091 prfm pstl1strm, [x4] | 5c: c87f1885 ldxp x5, x6, [x4] | 60: ca0000a5 eor x5, x5, x0 | 64: ca0100c6 eor x6, x6, x1 | 68: aa0600a6 orr x6, x5, x6 | 6c: b5000066 cbnz x6, 78 <foo+0x78> | 70: c8250c82 stxp w5, x2, x3, [x4] | 74: 35ffff45 cbnz w5, 5c <foo+0x5c> | 78: f9400480 ldr x0, [x4, #8] | 7c: d50323bf autiasp | 80: ca0000e0 eor x0, x7, x0 | 84: d65f03c0 ret ... sampling the high 8 bytes before and after the cmpxchg, and performing an EOR, as we'd expect. For backporting, I've tested this atop linux-4.9.y with GCC 5.5.0. Note that linux-4.9.y is oldest currently supported stable release, and mandates GCC 5.1+. Unfortunately I couldn't get a GCC 5.1 binary to run on my machines due to library incompatibilities. I've also used a standalone test to check that we can use a __uint128_t pointer in a +Q constraint at least as far back as GCC 4.8.5 and LLVM 3.9.1. Fixes: 5284e1b4bc8a ("arm64: xchg: Implement cmpxchg_double") Fixes: e9a4b795652f ("arm64: cmpxchg_dbl: patch in lse instructions when supported by the CPU") Reported-by: Boqun Feng <boqun.feng(a)gmail.com> Link: https://lore.kernel.org/lkml/Y6DEfQXymYVgL3oJ@boqun-archlinux/ Reported-by: Peter Zijlstra <peterz(a)infradead.org> Link: https://lore.kernel.org/lkml/Y6GXoO4qmH9OIZ5Q@hirez.programming.kicks-ass.n… Signed-off-by: Mark Rutland <mark.rutland(a)arm.com> Cc: stable(a)vger.kernel.org Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Steve Capper <steve.capper(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Link: https://lore.kernel.org/r/20230104151626.3262137-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will(a)kernel.org> diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h index 0890e4f568fb..cbb3d961123b 100644 --- a/arch/arm64/include/asm/atomic_ll_sc.h +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -315,7 +315,7 @@ __ll_sc__cmpxchg_double##name(unsigned long old1, \ " cbnz %w0, 1b\n" \ " " #mb "\n" \ "2:" \ - : "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \ + : "=&r" (tmp), "=&r" (ret), "+Q" (*(__uint128_t *)ptr) \ : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \ : cl); \ \ diff --git a/arch/arm64/include/asm/atomic_lse.h b/arch/arm64/include/asm/atomic_lse.h index 52075e93de6c..a94d6dacc029 100644 --- a/arch/arm64/include/asm/atomic_lse.h +++ b/arch/arm64/include/asm/atomic_lse.h @@ -311,7 +311,7 @@ __lse__cmpxchg_double##name(unsigned long old1, \ " eor %[old2], %[old2], %[oldval2]\n" \ " orr %[old1], %[old1], %[old2]" \ : [old1] "+&r" (x0), [old2] "+&r" (x1), \ - [v] "+Q" (*(unsigned long *)ptr) \ + [v] "+Q" (*(__uint128_t *)ptr) \ : [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \ [oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \ : cl); \

2 years, 1 month

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FAILED: patch "[PATCH] arm64: cmpxchg_double*: hazard against entire exchange" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-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>. Possible dependencies: 031af50045ea ("arm64: cmpxchg_double*: hazard against entire exchange variable") b2c3ccbd0011 ("arm64: atomics: remove LL/SC trampolines") 8e6082e94aac ("arm64: atomics: format whitespace consistently") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 031af50045ea97ed4386eb3751ca2c134d0fc911 Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland(a)arm.com> Date: Wed, 4 Jan 2023 15:16:26 +0000 Subject: [PATCH] arm64: cmpxchg_double*: hazard against entire exchange variable The inline assembly for arm64's cmpxchg_double*() implementations use a +Q constraint to hazard against other accesses to the memory location being exchanged. However, the pointer passed to the constraint is a pointer to unsigned long, and thus the hazard only applies to the first 8 bytes of the location. GCC can take advantage of this, assuming that other portions of the location are unchanged, leading to a number of potential problems. This is similar to what we fixed back in commit: fee960bed5e857eb ("arm64: xchg: hazard against entire exchange variable") ... but we forgot to adjust cmpxchg_double*() similarly at the same time. The same problem applies, as demonstrated with the following test: | struct big { | u64 lo, hi; | } __aligned(128); | | unsigned long foo(struct big *b) | { | u64 hi_old, hi_new; | | hi_old = b->hi; | cmpxchg_double_local(&b->lo, &b->hi, 0x12, 0x34, 0x56, 0x78); | hi_new = b->hi; | | return hi_old ^ hi_new; | } ... which GCC 12.1.0 compiles as: | 0000000000000000 <foo>: | 0: d503233f paciasp | 4: aa0003e4 mov x4, x0 | 8: 1400000e b 40 <foo+0x40> | c: d2800240 mov x0, #0x12 // #18 | 10: d2800681 mov x1, #0x34 // #52 | 14: aa0003e5 mov x5, x0 | 18: aa0103e6 mov x6, x1 | 1c: d2800ac2 mov x2, #0x56 // #86 | 20: d2800f03 mov x3, #0x78 // #120 | 24: 48207c82 casp x0, x1, x2, x3, [x4] | 28: ca050000 eor x0, x0, x5 | 2c: ca060021 eor x1, x1, x6 | 30: aa010000 orr x0, x0, x1 | 34: d2800000 mov x0, #0x0 // #0 <--- BANG | 38: d50323bf autiasp | 3c: d65f03c0 ret | 40: d2800240 mov x0, #0x12 // #18 | 44: d2800681 mov x1, #0x34 // #52 | 48: d2800ac2 mov x2, #0x56 // #86 | 4c: d2800f03 mov x3, #0x78 // #120 | 50: f9800091 prfm pstl1strm, [x4] | 54: c87f1885 ldxp x5, x6, [x4] | 58: ca0000a5 eor x5, x5, x0 | 5c: ca0100c6 eor x6, x6, x1 | 60: aa0600a6 orr x6, x5, x6 | 64: b5000066 cbnz x6, 70 <foo+0x70> | 68: c8250c82 stxp w5, x2, x3, [x4] | 6c: 35ffff45 cbnz w5, 54 <foo+0x54> | 70: d2800000 mov x0, #0x0 // #0 <--- BANG | 74: d50323bf autiasp | 78: d65f03c0 ret Notice that at the lines with "BANG" comments, GCC has assumed that the higher 8 bytes are unchanged by the cmpxchg_double() call, and that `hi_old ^ hi_new` can be reduced to a constant zero, for both LSE and LL/SC versions of cmpxchg_double(). This patch fixes the issue by passing a pointer to __uint128_t into the +Q constraint, ensuring that the compiler hazards against the entire 16 bytes being modified. With this change, GCC 12.1.0 compiles the above test as: | 0000000000000000 <foo>: | 0: f9400407 ldr x7, [x0, #8] | 4: d503233f paciasp | 8: aa0003e4 mov x4, x0 | c: 1400000f b 48 <foo+0x48> | 10: d2800240 mov x0, #0x12 // #18 | 14: d2800681 mov x1, #0x34 // #52 | 18: aa0003e5 mov x5, x0 | 1c: aa0103e6 mov x6, x1 | 20: d2800ac2 mov x2, #0x56 // #86 | 24: d2800f03 mov x3, #0x78 // #120 | 28: 48207c82 casp x0, x1, x2, x3, [x4] | 2c: ca050000 eor x0, x0, x5 | 30: ca060021 eor x1, x1, x6 | 34: aa010000 orr x0, x0, x1 | 38: f9400480 ldr x0, [x4, #8] | 3c: d50323bf autiasp | 40: ca0000e0 eor x0, x7, x0 | 44: d65f03c0 ret | 48: d2800240 mov x0, #0x12 // #18 | 4c: d2800681 mov x1, #0x34 // #52 | 50: d2800ac2 mov x2, #0x56 // #86 | 54: d2800f03 mov x3, #0x78 // #120 | 58: f9800091 prfm pstl1strm, [x4] | 5c: c87f1885 ldxp x5, x6, [x4] | 60: ca0000a5 eor x5, x5, x0 | 64: ca0100c6 eor x6, x6, x1 | 68: aa0600a6 orr x6, x5, x6 | 6c: b5000066 cbnz x6, 78 <foo+0x78> | 70: c8250c82 stxp w5, x2, x3, [x4] | 74: 35ffff45 cbnz w5, 5c <foo+0x5c> | 78: f9400480 ldr x0, [x4, #8] | 7c: d50323bf autiasp | 80: ca0000e0 eor x0, x7, x0 | 84: d65f03c0 ret ... sampling the high 8 bytes before and after the cmpxchg, and performing an EOR, as we'd expect. For backporting, I've tested this atop linux-4.9.y with GCC 5.5.0. Note that linux-4.9.y is oldest currently supported stable release, and mandates GCC 5.1+. Unfortunately I couldn't get a GCC 5.1 binary to run on my machines due to library incompatibilities. I've also used a standalone test to check that we can use a __uint128_t pointer in a +Q constraint at least as far back as GCC 4.8.5 and LLVM 3.9.1. Fixes: 5284e1b4bc8a ("arm64: xchg: Implement cmpxchg_double") Fixes: e9a4b795652f ("arm64: cmpxchg_dbl: patch in lse instructions when supported by the CPU") Reported-by: Boqun Feng <boqun.feng(a)gmail.com> Link: https://lore.kernel.org/lkml/Y6DEfQXymYVgL3oJ@boqun-archlinux/ Reported-by: Peter Zijlstra <peterz(a)infradead.org> Link: https://lore.kernel.org/lkml/Y6GXoO4qmH9OIZ5Q@hirez.programming.kicks-ass.n… Signed-off-by: Mark Rutland <mark.rutland(a)arm.com> Cc: stable(a)vger.kernel.org Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Steve Capper <steve.capper(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Link: https://lore.kernel.org/r/20230104151626.3262137-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will(a)kernel.org> diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h index 0890e4f568fb..cbb3d961123b 100644 --- a/arch/arm64/include/asm/atomic_ll_sc.h +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -315,7 +315,7 @@ __ll_sc__cmpxchg_double##name(unsigned long old1, \ " cbnz %w0, 1b\n" \ " " #mb "\n" \ "2:" \ - : "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \ + : "=&r" (tmp), "=&r" (ret), "+Q" (*(__uint128_t *)ptr) \ : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \ : cl); \ \ diff --git a/arch/arm64/include/asm/atomic_lse.h b/arch/arm64/include/asm/atomic_lse.h index 52075e93de6c..a94d6dacc029 100644 --- a/arch/arm64/include/asm/atomic_lse.h +++ b/arch/arm64/include/asm/atomic_lse.h @@ -311,7 +311,7 @@ __lse__cmpxchg_double##name(unsigned long old1, \ " eor %[old2], %[old2], %[oldval2]\n" \ " orr %[old1], %[old1], %[old2]" \ : [old1] "+&r" (x0), [old2] "+&r" (x1), \ - [v] "+Q" (*(unsigned long *)ptr) \ + [v] "+Q" (*(__uint128_t *)ptr) \ : [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \ [oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \ : cl); \

2 years, 1 month

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FAILED: patch "[PATCH] arm64: cmpxchg_double*: hazard against entire exchange" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-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>. Possible dependencies: 031af50045ea ("arm64: cmpxchg_double*: hazard against entire exchange variable") b2c3ccbd0011 ("arm64: atomics: remove LL/SC trampolines") 8e6082e94aac ("arm64: atomics: format whitespace consistently") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 031af50045ea97ed4386eb3751ca2c134d0fc911 Mon Sep 17 00:00:00 2001 From: Mark Rutland <mark.rutland(a)arm.com> Date: Wed, 4 Jan 2023 15:16:26 +0000 Subject: [PATCH] arm64: cmpxchg_double*: hazard against entire exchange variable The inline assembly for arm64's cmpxchg_double*() implementations use a +Q constraint to hazard against other accesses to the memory location being exchanged. However, the pointer passed to the constraint is a pointer to unsigned long, and thus the hazard only applies to the first 8 bytes of the location. GCC can take advantage of this, assuming that other portions of the location are unchanged, leading to a number of potential problems. This is similar to what we fixed back in commit: fee960bed5e857eb ("arm64: xchg: hazard against entire exchange variable") ... but we forgot to adjust cmpxchg_double*() similarly at the same time. The same problem applies, as demonstrated with the following test: | struct big { | u64 lo, hi; | } __aligned(128); | | unsigned long foo(struct big *b) | { | u64 hi_old, hi_new; | | hi_old = b->hi; | cmpxchg_double_local(&b->lo, &b->hi, 0x12, 0x34, 0x56, 0x78); | hi_new = b->hi; | | return hi_old ^ hi_new; | } ... which GCC 12.1.0 compiles as: | 0000000000000000 <foo>: | 0: d503233f paciasp | 4: aa0003e4 mov x4, x0 | 8: 1400000e b 40 <foo+0x40> | c: d2800240 mov x0, #0x12 // #18 | 10: d2800681 mov x1, #0x34 // #52 | 14: aa0003e5 mov x5, x0 | 18: aa0103e6 mov x6, x1 | 1c: d2800ac2 mov x2, #0x56 // #86 | 20: d2800f03 mov x3, #0x78 // #120 | 24: 48207c82 casp x0, x1, x2, x3, [x4] | 28: ca050000 eor x0, x0, x5 | 2c: ca060021 eor x1, x1, x6 | 30: aa010000 orr x0, x0, x1 | 34: d2800000 mov x0, #0x0 // #0 <--- BANG | 38: d50323bf autiasp | 3c: d65f03c0 ret | 40: d2800240 mov x0, #0x12 // #18 | 44: d2800681 mov x1, #0x34 // #52 | 48: d2800ac2 mov x2, #0x56 // #86 | 4c: d2800f03 mov x3, #0x78 // #120 | 50: f9800091 prfm pstl1strm, [x4] | 54: c87f1885 ldxp x5, x6, [x4] | 58: ca0000a5 eor x5, x5, x0 | 5c: ca0100c6 eor x6, x6, x1 | 60: aa0600a6 orr x6, x5, x6 | 64: b5000066 cbnz x6, 70 <foo+0x70> | 68: c8250c82 stxp w5, x2, x3, [x4] | 6c: 35ffff45 cbnz w5, 54 <foo+0x54> | 70: d2800000 mov x0, #0x0 // #0 <--- BANG | 74: d50323bf autiasp | 78: d65f03c0 ret Notice that at the lines with "BANG" comments, GCC has assumed that the higher 8 bytes are unchanged by the cmpxchg_double() call, and that `hi_old ^ hi_new` can be reduced to a constant zero, for both LSE and LL/SC versions of cmpxchg_double(). This patch fixes the issue by passing a pointer to __uint128_t into the +Q constraint, ensuring that the compiler hazards against the entire 16 bytes being modified. With this change, GCC 12.1.0 compiles the above test as: | 0000000000000000 <foo>: | 0: f9400407 ldr x7, [x0, #8] | 4: d503233f paciasp | 8: aa0003e4 mov x4, x0 | c: 1400000f b 48 <foo+0x48> | 10: d2800240 mov x0, #0x12 // #18 | 14: d2800681 mov x1, #0x34 // #52 | 18: aa0003e5 mov x5, x0 | 1c: aa0103e6 mov x6, x1 | 20: d2800ac2 mov x2, #0x56 // #86 | 24: d2800f03 mov x3, #0x78 // #120 | 28: 48207c82 casp x0, x1, x2, x3, [x4] | 2c: ca050000 eor x0, x0, x5 | 30: ca060021 eor x1, x1, x6 | 34: aa010000 orr x0, x0, x1 | 38: f9400480 ldr x0, [x4, #8] | 3c: d50323bf autiasp | 40: ca0000e0 eor x0, x7, x0 | 44: d65f03c0 ret | 48: d2800240 mov x0, #0x12 // #18 | 4c: d2800681 mov x1, #0x34 // #52 | 50: d2800ac2 mov x2, #0x56 // #86 | 54: d2800f03 mov x3, #0x78 // #120 | 58: f9800091 prfm pstl1strm, [x4] | 5c: c87f1885 ldxp x5, x6, [x4] | 60: ca0000a5 eor x5, x5, x0 | 64: ca0100c6 eor x6, x6, x1 | 68: aa0600a6 orr x6, x5, x6 | 6c: b5000066 cbnz x6, 78 <foo+0x78> | 70: c8250c82 stxp w5, x2, x3, [x4] | 74: 35ffff45 cbnz w5, 5c <foo+0x5c> | 78: f9400480 ldr x0, [x4, #8] | 7c: d50323bf autiasp | 80: ca0000e0 eor x0, x7, x0 | 84: d65f03c0 ret ... sampling the high 8 bytes before and after the cmpxchg, and performing an EOR, as we'd expect. For backporting, I've tested this atop linux-4.9.y with GCC 5.5.0. Note that linux-4.9.y is oldest currently supported stable release, and mandates GCC 5.1+. Unfortunately I couldn't get a GCC 5.1 binary to run on my machines due to library incompatibilities. I've also used a standalone test to check that we can use a __uint128_t pointer in a +Q constraint at least as far back as GCC 4.8.5 and LLVM 3.9.1. Fixes: 5284e1b4bc8a ("arm64: xchg: Implement cmpxchg_double") Fixes: e9a4b795652f ("arm64: cmpxchg_dbl: patch in lse instructions when supported by the CPU") Reported-by: Boqun Feng <boqun.feng(a)gmail.com> Link: https://lore.kernel.org/lkml/Y6DEfQXymYVgL3oJ@boqun-archlinux/ Reported-by: Peter Zijlstra <peterz(a)infradead.org> Link: https://lore.kernel.org/lkml/Y6GXoO4qmH9OIZ5Q@hirez.programming.kicks-ass.n… Signed-off-by: Mark Rutland <mark.rutland(a)arm.com> Cc: stable(a)vger.kernel.org Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Steve Capper <steve.capper(a)arm.com> Cc: Will Deacon <will(a)kernel.org> Link: https://lore.kernel.org/r/20230104151626.3262137-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will(a)kernel.org> diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h index 0890e4f568fb..cbb3d961123b 100644 --- a/arch/arm64/include/asm/atomic_ll_sc.h +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -315,7 +315,7 @@ __ll_sc__cmpxchg_double##name(unsigned long old1, \ " cbnz %w0, 1b\n" \ " " #mb "\n" \ "2:" \ - : "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \ + : "=&r" (tmp), "=&r" (ret), "+Q" (*(__uint128_t *)ptr) \ : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \ : cl); \ \ diff --git a/arch/arm64/include/asm/atomic_lse.h b/arch/arm64/include/asm/atomic_lse.h index 52075e93de6c..a94d6dacc029 100644 --- a/arch/arm64/include/asm/atomic_lse.h +++ b/arch/arm64/include/asm/atomic_lse.h @@ -311,7 +311,7 @@ __lse__cmpxchg_double##name(unsigned long old1, \ " eor %[old2], %[old2], %[oldval2]\n" \ " orr %[old1], %[old1], %[old2]" \ : [old1] "+&r" (x0), [old2] "+&r" (x1), \ - [v] "+Q" (*(unsigned long *)ptr) \ + [v] "+Q" (*(__uint128_t *)ptr) \ : [new1] "r" (x2), [new2] "r" (x3), [ptr] "r" (x4), \ [oldval1] "r" (oldval1), [oldval2] "r" (oldval2) \ : cl); \

2 years, 1 month

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FAILED: patch "[PATCH] io_uring: lock overflowing for IOPOLL" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-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>. Possible dependencies: 544d163d659d ("io_uring: lock overflowing for IOPOLL") a8cf95f93610 ("io_uring: fix overflow handling regression") fa18fa2272c7 ("io_uring: inline __io_req_complete_put()") f9d567c75ec2 ("io_uring: inline __io_req_complete_post()") 52120f0fadcb ("io_uring: add allow_overflow to io_post_aux_cqe") e6130eba8a84 ("io_uring: add support for passing fixed file descriptors") 253993210bd8 ("io_uring: introduce locking helpers for CQE posting") 305bef988708 ("io_uring: hide eventfd assumptions in eventfd paths") d9dee4302a7c ("io_uring: remove ->flush_cqes optimisation") a830ffd28780 ("io_uring: move io_eventfd_signal()") 9046c6415be6 ("io_uring: reshuffle io_uring/io_uring.h") d142c3ec8d16 ("io_uring: remove extra io_commit_cqring()") 68494a65d0e2 ("io_uring: introduce io_req_cqe_overflow()") faf88dde060f ("io_uring: don't inline __io_get_cqe()") d245bca6375b ("io_uring: don't expose io_fill_cqe_aux()") aa1e90f64ee5 ("io_uring: move small helpers to headers") aa1e90f64ee5 ("io_uring: move small helpers to headers") aa1e90f64ee5 ("io_uring: move small helpers to headers") aa1e90f64ee5 ("io_uring: move small helpers to headers") aa1e90f64ee5 ("io_uring: move small helpers to headers") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 544d163d659d45a206d8929370d5a2984e546cb7 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov <asml.silence(a)gmail.com> Date: Thu, 12 Jan 2023 13:08:56 +0000 Subject: [PATCH] io_uring: lock overflowing for IOPOLL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit syzbot reports an issue with overflow filling for IOPOLL: WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734 CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0 Workqueue: events_unbound io_ring_exit_work Call trace: io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734 io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773 io_fill_cqe_req io_uring/io_uring.h:168 [inline] io_do_iopoll+0x474/0x62c io_uring/rw.c:1065 io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513 io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056 io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863 There is no real problem for normal IOPOLL as flush is also called with uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL, for which __io_cqring_overflow_flush() happens from the CQ waiting path. Reported-and-tested-by: syzbot+6805087452d72929404e(a)syzkaller.appspotmail.com Cc: stable(a)vger.kernel.org # 5.10+ Signed-off-by: Pavel Begunkov <asml.silence(a)gmail.com> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/io_uring/rw.c b/io_uring/rw.c index 8227af2e1c0f..9c3ddd46a1ad 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -1062,7 +1062,11 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) continue; req->cqe.flags = io_put_kbuf(req, 0); - io_fill_cqe_req(req->ctx, req); + if (unlikely(!__io_fill_cqe_req(ctx, req))) { + spin_lock(&ctx->completion_lock); + io_req_cqe_overflow(req); + spin_unlock(&ctx->completion_lock); + } } if (unlikely(!nr_events))

2 years, 1 month

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FAILED: patch "[PATCH] efi: fix NULL-deref in init error path" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-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>. Possible dependencies: 703c13fe3c9a ("efi: fix NULL-deref in init error path") 1fff234de2b6 ("efi: x86: Move EFI runtime map sysfs code to arch/x86") 8dfac4d8ad27 ("efi: runtime-maps: Clarify purpose and enable by default for kexec") 4059ba656ce5 ("efi: memmap: Move EFI fake memmap support into x86 arch tree") d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support") 25519d683442 ("ima: generalize x86/EFI arch glue for other EFI architectures") 88e9a5b7965c ("efi/fake_mem: arrange for a resource entry per efi_fake_mem instance") 4d0a4388ccdd ("Merge branch 'efi/urgent' into efi/core, to pick up fixes") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 703c13fe3c9af557d312f5895ed6a5fda2711104 Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan+linaro(a)kernel.org> Date: Mon, 19 Dec 2022 10:10:04 +0100 Subject: [PATCH] efi: fix NULL-deref in init error path In cases where runtime services are not supported or have been disabled, the runtime services workqueue will never have been allocated. Do not try to destroy the workqueue unconditionally in the unlikely event that EFI initialisation fails to avoid dereferencing a NULL pointer. Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails") Cc: stable(a)vger.kernel.org Cc: Li Heng <liheng40(a)huawei.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> Signed-off-by: Ard Biesheuvel <ardb(a)kernel.org> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 09716eebe8ac..a2b0cbc8741c 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -394,8 +394,8 @@ static int __init efisubsys_init(void) efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { pr_err("efi: Firmware registration failed.\n"); - destroy_workqueue(efi_rts_wq); - return -ENOMEM; + error = -ENOMEM; + goto err_destroy_wq; } if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | @@ -443,7 +443,10 @@ static int __init efisubsys_init(void) err_put: kobject_put(efi_kobj); efi_kobj = NULL; - destroy_workqueue(efi_rts_wq); +err_destroy_wq: + if (efi_rts_wq) + destroy_workqueue(efi_rts_wq); + return error; }

2 years, 1 month

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FAILED: patch "[PATCH] efi: fix NULL-deref in init error path" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-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>. Possible dependencies: 703c13fe3c9a ("efi: fix NULL-deref in init error path") 1fff234de2b6 ("efi: x86: Move EFI runtime map sysfs code to arch/x86") 8dfac4d8ad27 ("efi: runtime-maps: Clarify purpose and enable by default for kexec") 4059ba656ce5 ("efi: memmap: Move EFI fake memmap support into x86 arch tree") d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support") 25519d683442 ("ima: generalize x86/EFI arch glue for other EFI architectures") 88e9a5b7965c ("efi/fake_mem: arrange for a resource entry per efi_fake_mem instance") 4d0a4388ccdd ("Merge branch 'efi/urgent' into efi/core, to pick up fixes") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 703c13fe3c9af557d312f5895ed6a5fda2711104 Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan+linaro(a)kernel.org> Date: Mon, 19 Dec 2022 10:10:04 +0100 Subject: [PATCH] efi: fix NULL-deref in init error path In cases where runtime services are not supported or have been disabled, the runtime services workqueue will never have been allocated. Do not try to destroy the workqueue unconditionally in the unlikely event that EFI initialisation fails to avoid dereferencing a NULL pointer. Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails") Cc: stable(a)vger.kernel.org Cc: Li Heng <liheng40(a)huawei.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> Signed-off-by: Ard Biesheuvel <ardb(a)kernel.org> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 09716eebe8ac..a2b0cbc8741c 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -394,8 +394,8 @@ static int __init efisubsys_init(void) efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { pr_err("efi: Firmware registration failed.\n"); - destroy_workqueue(efi_rts_wq); - return -ENOMEM; + error = -ENOMEM; + goto err_destroy_wq; } if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | @@ -443,7 +443,10 @@ static int __init efisubsys_init(void) err_put: kobject_put(efi_kobj); efi_kobj = NULL; - destroy_workqueue(efi_rts_wq); +err_destroy_wq: + if (efi_rts_wq) + destroy_workqueue(efi_rts_wq); + return error; }

2 years, 1 month

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FAILED: patch "[PATCH] efi: fix NULL-deref in init error path" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-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>. Possible dependencies: 703c13fe3c9a ("efi: fix NULL-deref in init error path") 1fff234de2b6 ("efi: x86: Move EFI runtime map sysfs code to arch/x86") 8dfac4d8ad27 ("efi: runtime-maps: Clarify purpose and enable by default for kexec") 4059ba656ce5 ("efi: memmap: Move EFI fake memmap support into x86 arch tree") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 703c13fe3c9af557d312f5895ed6a5fda2711104 Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan+linaro(a)kernel.org> Date: Mon, 19 Dec 2022 10:10:04 +0100 Subject: [PATCH] efi: fix NULL-deref in init error path In cases where runtime services are not supported or have been disabled, the runtime services workqueue will never have been allocated. Do not try to destroy the workqueue unconditionally in the unlikely event that EFI initialisation fails to avoid dereferencing a NULL pointer. Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails") Cc: stable(a)vger.kernel.org Cc: Li Heng <liheng40(a)huawei.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> Signed-off-by: Ard Biesheuvel <ardb(a)kernel.org> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 09716eebe8ac..a2b0cbc8741c 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -394,8 +394,8 @@ static int __init efisubsys_init(void) efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { pr_err("efi: Firmware registration failed.\n"); - destroy_workqueue(efi_rts_wq); - return -ENOMEM; + error = -ENOMEM; + goto err_destroy_wq; } if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | @@ -443,7 +443,10 @@ static int __init efisubsys_init(void) err_put: kobject_put(efi_kobj); efi_kobj = NULL; - destroy_workqueue(efi_rts_wq); +err_destroy_wq: + if (efi_rts_wq) + destroy_workqueue(efi_rts_wq); + return error; }

2 years, 1 month

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FAILED: patch "[PATCH] efi: fix NULL-deref in init error path" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-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>. Possible dependencies: 703c13fe3c9a ("efi: fix NULL-deref in init error path") 1fff234de2b6 ("efi: x86: Move EFI runtime map sysfs code to arch/x86") 8dfac4d8ad27 ("efi: runtime-maps: Clarify purpose and enable by default for kexec") 4059ba656ce5 ("efi: memmap: Move EFI fake memmap support into x86 arch tree") d391c5827107 ("drivers/firmware: move x86 Generic System Framebuffers support") 25519d683442 ("ima: generalize x86/EFI arch glue for other EFI architectures") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 703c13fe3c9af557d312f5895ed6a5fda2711104 Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan+linaro(a)kernel.org> Date: Mon, 19 Dec 2022 10:10:04 +0100 Subject: [PATCH] efi: fix NULL-deref in init error path In cases where runtime services are not supported or have been disabled, the runtime services workqueue will never have been allocated. Do not try to destroy the workqueue unconditionally in the unlikely event that EFI initialisation fails to avoid dereferencing a NULL pointer. Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails") Cc: stable(a)vger.kernel.org Cc: Li Heng <liheng40(a)huawei.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> Signed-off-by: Ard Biesheuvel <ardb(a)kernel.org> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 09716eebe8ac..a2b0cbc8741c 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -394,8 +394,8 @@ static int __init efisubsys_init(void) efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { pr_err("efi: Firmware registration failed.\n"); - destroy_workqueue(efi_rts_wq); - return -ENOMEM; + error = -ENOMEM; + goto err_destroy_wq; } if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | @@ -443,7 +443,10 @@ static int __init efisubsys_init(void) err_put: kobject_put(efi_kobj); efi_kobj = NULL; - destroy_workqueue(efi_rts_wq); +err_destroy_wq: + if (efi_rts_wq) + destroy_workqueue(efi_rts_wq); + return error; }

2 years, 1 month

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FAILED: patch "[PATCH] efi: fix NULL-deref in init error path" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-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>. Possible dependencies: 703c13fe3c9a ("efi: fix NULL-deref in init error path") 1fff234de2b6 ("efi: x86: Move EFI runtime map sysfs code to arch/x86") 8dfac4d8ad27 ("efi: runtime-maps: Clarify purpose and enable by default for kexec") 4059ba656ce5 ("efi: memmap: Move EFI fake memmap support into x86 arch tree") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 703c13fe3c9af557d312f5895ed6a5fda2711104 Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan+linaro(a)kernel.org> Date: Mon, 19 Dec 2022 10:10:04 +0100 Subject: [PATCH] efi: fix NULL-deref in init error path In cases where runtime services are not supported or have been disabled, the runtime services workqueue will never have been allocated. Do not try to destroy the workqueue unconditionally in the unlikely event that EFI initialisation fails to avoid dereferencing a NULL pointer. Fixes: 98086df8b70c ("efi: add missed destroy_workqueue when efisubsys_init fails") Cc: stable(a)vger.kernel.org Cc: Li Heng <liheng40(a)huawei.com> Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> Signed-off-by: Ard Biesheuvel <ardb(a)kernel.org> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 09716eebe8ac..a2b0cbc8741c 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -394,8 +394,8 @@ static int __init efisubsys_init(void) efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { pr_err("efi: Firmware registration failed.\n"); - destroy_workqueue(efi_rts_wq); - return -ENOMEM; + error = -ENOMEM; + goto err_destroy_wq; } if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | @@ -443,7 +443,10 @@ static int __init efisubsys_init(void) err_put: kobject_put(efi_kobj); efi_kobj = NULL; - destroy_workqueue(efi_rts_wq); +err_destroy_wq: + if (efi_rts_wq) + destroy_workqueue(efi_rts_wq); + return error; }

2 years, 1 month

1
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