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| author | Evgeny Eremin <e.eremin@omprussia.ru> | 2020-07-08 14:18:19 +0200 |
|---|---|---|
| committer | Dmitry V. Levin <ldv@altlinux.org> | 2020-11-16 08:00:00 +0000 |
| commit | bad8d5ff60ab68c81643685e27f0ed5161a0495a (patch) | |
| tree | d2801b033c60a950e721f8ad58cde5dac46519e3 | |
| parent | d64ad0a5172207f00d91a05c91e1500b0d80b2c2 (diff) | |
| download | glibc-bad8d5ff60ab68c81643685e27f0ed5161a0495a.tar.gz glibc-bad8d5ff60ab68c81643685e27f0ed5161a0495a.tar.xz glibc-bad8d5ff60ab68c81643685e27f0ed5161a0495a.zip | |
arm: CVE-2020-6096: fix memcpy and memmove for negative length [BZ #25620]
Unsigned branch instructions could be used for r2 to fix the wrong behavior when a negative length is passed to memcpy and memmove. This commit fixes the generic arm implementation of memcpy amd memmove. (cherry picked from commit 79a4fa341b8a89cb03f84564fd72abaa1a2db394)
| -rw-r--r-- | sysdeps/arm/memcpy.S | 24 | ||||
| -rw-r--r-- | sysdeps/arm/memmove.S | 24 |
2 files changed, 20 insertions, 28 deletions
diff --git a/sysdeps/arm/memcpy.S b/sysdeps/arm/memcpy.S index cba8609813..7b4214aae9 100644 --- a/sysdeps/arm/memcpy.S +++ b/sysdeps/arm/memcpy.S @@ -68,7 +68,7 @@ ENTRY(memcpy) cfi_remember_state subs r2, r2, #4 - blt 8f + blo 8f ands ip, r0, #3 PLD( pld [r1, #0] ) bne 9f @@ -82,7 +82,7 @@ ENTRY(memcpy) cfi_rel_offset (r6, 4) cfi_rel_offset (r7, 8) cfi_rel_offset (r8, 12) - blt 5f + blo 5f CALGN( ands ip, r1, #31 ) CALGN( rsb r3, ip, #32 ) @@ -98,9 +98,9 @@ ENTRY(memcpy) #endif PLD( pld [r1, #0] ) -2: PLD( subs r2, r2, #96 ) +2: PLD( cmp r2, #96 ) PLD( pld [r1, #28] ) - PLD( blt 4f ) + PLD( blo 4f ) PLD( pld [r1, #60] ) PLD( pld [r1, #92] ) @@ -108,9 +108,7 @@ ENTRY(memcpy) 4: ldmia r1!, {r3, r4, r5, r6, r7, r8, ip, lr} subs r2, r2, #32 stmia r0!, {r3, r4, r5, r6, r7, r8, ip, lr} - bge 3b - PLD( cmn r2, #96 ) - PLD( bge 4b ) + bhs 3b 5: ands ip, r2, #28 rsb ip, ip, #32 @@ -222,7 +220,7 @@ ENTRY(memcpy) strbge r4, [r0], #1 subs r2, r2, ip strb lr, [r0], #1 - blt 8b + blo 8b ands ip, r1, #3 beq 1b @@ -236,7 +234,7 @@ ENTRY(memcpy) .macro forward_copy_shift pull push subs r2, r2, #28 - blt 14f + blo 14f CALGN( ands ip, r1, #31 ) CALGN( rsb ip, ip, #32 ) @@ -253,9 +251,9 @@ ENTRY(memcpy) cfi_rel_offset (r10, 16) PLD( pld [r1, #0] ) - PLD( subs r2, r2, #96 ) + PLD( cmp r2, #96 ) PLD( pld [r1, #28] ) - PLD( blt 13f ) + PLD( blo 13f ) PLD( pld [r1, #60] ) PLD( pld [r1, #92] ) @@ -280,9 +278,7 @@ ENTRY(memcpy) mov ip, ip, PULL #\pull orr ip, ip, lr, PUSH #\push stmia r0!, {r3, r4, r5, r6, r7, r8, r10, ip} - bge 12b - PLD( cmn r2, #96 ) - PLD( bge 13b ) + bhs 12b pop {r5 - r8, r10} cfi_adjust_cfa_offset (-20) diff --git a/sysdeps/arm/memmove.S b/sysdeps/arm/memmove.S index 74d3042043..b28a811912 100644 --- a/sysdeps/arm/memmove.S +++ b/sysdeps/arm/memmove.S @@ -85,7 +85,7 @@ ENTRY(memmove) add r1, r1, r2 add r0, r0, r2 subs r2, r2, #4 - blt 8f + blo 8f ands ip, r0, #3 PLD( pld [r1, #-4] ) bne 9f @@ -99,7 +99,7 @@ ENTRY(memmove) cfi_rel_offset (r6, 4) cfi_rel_offset (r7, 8) cfi_rel_offset (r8, 12) - blt 5f + blo 5f CALGN( ands ip, r1, #31 ) CALGN( sbcsne r4, ip, r2 ) @ C is always set here @@ -114,9 +114,9 @@ ENTRY(memmove) #endif PLD( pld [r1, #-4] ) -2: PLD( subs r2, r2, #96 ) +2: PLD( cmp r2, #96 ) PLD( pld [r1, #-32] ) - PLD( blt 4f ) + PLD( blo 4f ) PLD( pld [r1, #-64] ) PLD( pld [r1, #-96] ) @@ -124,9 +124,7 @@ ENTRY(memmove) 4: ldmdb r1!, {r3, r4, r5, r6, r7, r8, ip, lr} subs r2, r2, #32 stmdb r0!, {r3, r4, r5, r6, r7, r8, ip, lr} - bge 3b - PLD( cmn r2, #96 ) - PLD( bge 4b ) + bhs 3b 5: ands ip, r2, #28 rsb ip, ip, #32 @@ -237,7 +235,7 @@ ENTRY(memmove) strbge r4, [r0, #-1]! subs r2, r2, ip strb lr, [r0, #-1]! - blt 8b + blo 8b ands ip, r1, #3 beq 1b @@ -251,7 +249,7 @@ ENTRY(memmove) .macro backward_copy_shift push pull subs r2, r2, #28 - blt 14f + blo 14f CALGN( ands ip, r1, #31 ) CALGN( rsb ip, ip, #32 ) @@ -268,9 +266,9 @@ ENTRY(memmove) cfi_rel_offset (r10, 16) PLD( pld [r1, #-4] ) - PLD( subs r2, r2, #96 ) + PLD( cmp r2, #96 ) PLD( pld [r1, #-32] ) - PLD( blt 13f ) + PLD( blo 13f ) PLD( pld [r1, #-64] ) PLD( pld [r1, #-96] ) @@ -295,9 +293,7 @@ ENTRY(memmove) mov r4, r4, PUSH #\push orr r4, r4, r3, PULL #\pull stmdb r0!, {r4 - r8, r10, ip, lr} - bge 12b - PLD( cmn r2, #96 ) - PLD( bge 13b ) + bhs 12b pop {r5 - r8, r10} cfi_adjust_cfa_offset (-20) |