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| author | Evgeny Eremin <e.eremin@omprussia.ru> | 2020-07-08 14:18:19 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2020-07-08 14:18:19 +0200 |
| commit | 79a4fa341b8a89cb03f84564fd72abaa1a2db394 (patch) | |
| tree | d3ea863dacd3ed778ff7e8ef825162a62d49ce2e /sysdeps/arm/memmove.S | |
| parent | 78e02c469828fcfb6a5cf73dbcceb4f60fb6fafd (diff) | |
| download | glibc-79a4fa341b8a89cb03f84564fd72abaa1a2db394.tar.gz glibc-79a4fa341b8a89cb03f84564fd72abaa1a2db394.tar.xz glibc-79a4fa341b8a89cb03f84564fd72abaa1a2db394.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.
Diffstat (limited to 'sysdeps/arm/memmove.S')
| -rw-r--r-- | sysdeps/arm/memmove.S | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/sysdeps/arm/memmove.S b/sysdeps/arm/memmove.S index 954037ef3a..0d07b76ee6 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) |