package/musl: add upstream security fixes for CVE-2019-14697

Fixes CVE-2019-14697: musl libc 1.1.23 and earlier x87 float stack imbalance

For more details, see the oss-security discussion:
https://www.openwall.com/lists/oss-security/2019/08/05/6

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

diff --git a/package/musl/0004-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch b/package/musl/0004-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch
new file mode 100644 (file)
index 0000000..8940c28
--- /dev/null
+++ b/package/musl/0004-fix-x87-stack-imbalance-in-corner-cases-of-i386-math.patch
@@ -0,0 +1,200 @@
+From f3ed8bfe8a82af1870ddc8696ed4cc1d5aa6b441 Mon Sep 17 00:00:00 2001
+From: Rich Felker <dalias@aerifal.cx>
+Date: Mon, 5 Aug 2019 18:41:47 -0400
+Subject: [PATCH] fix x87 stack imbalance in corner cases of i386 math asm
+
+commit 31c5fb80b9eae86f801be4f46025bc6532a554c5 introduced underflow
+code paths for the i386 math asm, along with checks on the fpu status
+word to skip the underflow-generation instructions if the underflow
+flag was already raised. unfortunately, at least one such path, in
+log1p, returned with 2 items on the x87 stack rather than just 1 item
+for the return value. this is a violation of the ABI's calling
+convention, and could cause subsequent floating point code to produce
+NANs due to x87 stack overflow. if floating point results are used in
+flow control, this can lead to runaway wrong code execution.
+
+rather than reviewing each "underflow already raised" code path for
+correctness, remove them all. they're likely slower than just
+performing the underflow code unconditionally, and significantly more
+complex.
+
+all of this code should be ripped out and replaced by C source files
+with inline asm. doing so would preclude this kind of error by having
+the compiler perform all x87 stack register allocation and stack
+manipulation, and would produce comparable or better code. however
+such a change is a much larger project.
+
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ src/math/i386/asin.s   | 10 ++--------
+ src/math/i386/atan.s   |  7 ++-----
+ src/math/i386/atan2.s  |  5 +----
+ src/math/i386/atan2f.s |  5 +----
+ src/math/i386/atanf.s  |  7 ++-----
+ src/math/i386/exp.s    | 10 ++--------
+ src/math/i386/log1p.s  |  7 ++-----
+ src/math/i386/log1pf.s |  7 ++-----
+ 8 files changed, 14 insertions(+), 44 deletions(-)
+
+diff --git a/src/math/i386/asin.s b/src/math/i386/asin.s
+index a9f691bf..920d967a 100644
+--- a/src/math/i386/asin.s
++++ b/src/math/i386/asin.s
+@@ -7,13 +7,10 @@ asinf:
+       cmp $0x01000000,%eax
+       jae 1f
+               # subnormal x, return x with underflow
+-      fnstsw %ax
+-      and $16,%ax
+-      jnz 2f
+       fld %st(0)
+       fmul %st(1)
+       fstps 4(%esp)
+-2:    ret
++      ret
+ 
+ .global asinl
+ .type asinl,@function
+@@ -30,11 +27,8 @@ asin:
+       cmp $0x00200000,%eax
+       jae 1f
+               # subnormal x, return x with underflow
+-      fnstsw %ax
+-      and $16,%ax
+-      jnz 2f
+       fsts 4(%esp)
+-2:    ret
++      ret
+ 1:    fld %st(0)
+       fld1
+       fsub %st(0),%st(1)
+diff --git a/src/math/i386/atan.s b/src/math/i386/atan.s
+index d73137b2..a26feae1 100644
+--- a/src/math/i386/atan.s
++++ b/src/math/i386/atan.s
+@@ -10,8 +10,5 @@ atan:
+       fpatan
+       ret
+               # subnormal x, return x with underflow
+-1:    fnstsw %ax
+-      and $16,%ax
+-      jnz 2f
+-      fsts 4(%esp)
+-2:    ret
++1:    fsts 4(%esp)
++      ret
+diff --git a/src/math/i386/atan2.s b/src/math/i386/atan2.s
+index a7d2979b..1fa0524d 100644
+--- a/src/math/i386/atan2.s
++++ b/src/math/i386/atan2.s
+@@ -10,8 +10,5 @@ atan2:
+       cmp $0x00200000,%eax
+       jae 1f
+               # subnormal x, return x with underflow
+-      fnstsw %ax
+-      and $16,%ax
+-      jnz 1f
+       fsts 4(%esp)
+-1:    ret
++      ret
+diff --git a/src/math/i386/atan2f.s b/src/math/i386/atan2f.s
+index 14b88ce5..0b264726 100644
+--- a/src/math/i386/atan2f.s
++++ b/src/math/i386/atan2f.s
+@@ -10,10 +10,7 @@ atan2f:
+       cmp $0x01000000,%eax
+       jae 1f
+               # subnormal x, return x with underflow
+-      fnstsw %ax
+-      and $16,%ax
+-      jnz 1f
+       fld %st(0)
+       fmul %st(1)
+       fstps 4(%esp)
+-1:    ret
++      ret
+diff --git a/src/math/i386/atanf.s b/src/math/i386/atanf.s
+index 8caddefa..893beac5 100644
+--- a/src/math/i386/atanf.s
++++ b/src/math/i386/atanf.s
+@@ -10,10 +10,7 @@ atanf:
+       fpatan
+       ret
+               # subnormal x, return x with underflow
+-1:    fnstsw %ax
+-      and $16,%ax
+-      jnz 2f
+-      fld %st(0)
++1:    fld %st(0)
+       fmul %st(1)
+       fstps 4(%esp)
+-2:    ret
++      ret
+diff --git a/src/math/i386/exp.s b/src/math/i386/exp.s
+index c7aa5b6e..df87c497 100644
+--- a/src/math/i386/exp.s
++++ b/src/math/i386/exp.s
+@@ -7,13 +7,10 @@ expm1f:
+       cmp $0x01000000,%eax
+       jae 1f
+               # subnormal x, return x with underflow
+-      fnstsw %ax
+-      and $16,%ax
+-      jnz 2f
+       fld %st(0)
+       fmul %st(1)
+       fstps 4(%esp)
+-2:    ret
++      ret
+ 
+ .global expm1l
+ .type expm1l,@function
+@@ -30,11 +27,8 @@ expm1:
+       cmp $0x00200000,%eax
+       jae 1f
+               # subnormal x, return x with underflow
+-      fnstsw %ax
+-      and $16,%ax
+-      jnz 2f
+       fsts 4(%esp)
+-2:    ret
++      ret
+ 1:    fldl2e
+       fmulp
+       mov $0xc2820000,%eax
+diff --git a/src/math/i386/log1p.s b/src/math/i386/log1p.s
+index 6b6929c7..354f391a 100644
+--- a/src/math/i386/log1p.s
++++ b/src/math/i386/log1p.s
+@@ -16,9 +16,6 @@ log1p:
+       fyl2x
+       ret
+               # subnormal x, return x with underflow
+-2:    fnstsw %ax
+-      and $16,%ax
+-      jnz 1f
+-      fsts 4(%esp)
++2:    fsts 4(%esp)
+       fstp %st(1)
+-1:    ret
++      ret
+diff --git a/src/math/i386/log1pf.s b/src/math/i386/log1pf.s
+index c0bcd30f..4d3484cd 100644
+--- a/src/math/i386/log1pf.s
++++ b/src/math/i386/log1pf.s
+@@ -16,10 +16,7 @@ log1pf:
+       fyl2x
+       ret
+               # subnormal x, return x with underflow
+-2:    fnstsw %ax
+-      and $16,%ax
+-      jnz 1f
+-      fxch
++2:    fxch
+       fmul %st(1)
+       fstps 4(%esp)
+-1:    ret
++      ret
+-- 
+2.11.0
+

diff --git a/package/musl/0005-fix-build-regression-in-i386-asm-for-atan2-atan2f.patch b/package/musl/0005-fix-build-regression-in-i386-asm-for-atan2-atan2f.patch
new file mode 100644 (file)
index 0000000..824933c
--- /dev/null
+++ b/package/musl/0005-fix-build-regression-in-i386-asm-for-atan2-atan2f.patch
@@ -0,0 +1,37 @@
+From 6818c31c9bc4bbad5357f1de14bedf781e5b349e Mon Sep 17 00:00:00 2001
+From: Rich Felker <dalias@aerifal.cx>
+Date: Mon, 5 Aug 2019 19:57:07 -0400
+Subject: [PATCH] fix build regression in i386 asm for atan2, atan2f
+
+commit f3ed8bfe8a82af1870ddc8696ed4cc1d5aa6b441 inadvertently removed
+labels that were still needed.
+
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ src/math/i386/atan2.s  | 2 +-
+ src/math/i386/atan2f.s | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/math/i386/atan2.s b/src/math/i386/atan2.s
+index 1fa0524d..76b95f31 100644
+--- a/src/math/i386/atan2.s
++++ b/src/math/i386/atan2.s
+@@ -11,4 +11,4 @@ atan2:
+       jae 1f
+               # subnormal x, return x with underflow
+       fsts 4(%esp)
+-      ret
++1:    ret
+diff --git a/src/math/i386/atan2f.s b/src/math/i386/atan2f.s
+index 0b264726..c9408a90 100644
+--- a/src/math/i386/atan2f.s
++++ b/src/math/i386/atan2f.s
+@@ -13,4 +13,4 @@ atan2f:
+       fld %st(0)
+       fmul %st(1)
+       fstps 4(%esp)
+-      ret
++1:    ret
+-- 
+2.11.0
+