From: Greg Kroah-Hartman Date: Fri, 9 Apr 2021 06:24:30 +0000 (+0200) Subject: 4.4-stable patches X-Git-Tag: v4.4.266~15 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a20421f2b47264804fd80afdf42c0e4ad0b31614;p=thirdparty%2Fkernel%2Fstable-queue.git 4.4-stable patches added patches: bpf-x86-validate-computation-of-branch-displacements-for-x86-64.patch --- diff --git a/queue-4.4/bpf-x86-validate-computation-of-branch-displacements-for-x86-64.patch b/queue-4.4/bpf-x86-validate-computation-of-branch-displacements-for-x86-64.patch new file mode 100644 index 00000000000..cd780b9fe17 --- /dev/null +++ b/queue-4.4/bpf-x86-validate-computation-of-branch-displacements-for-x86-64.patch @@ -0,0 +1,60 @@ +From e4d4d456436bfb2fe412ee2cd489f7658449b098 Mon Sep 17 00:00:00 2001 +From: Piotr Krysiuk +Date: Mon, 5 Apr 2021 22:52:15 +0100 +Subject: bpf, x86: Validate computation of branch displacements for x86-64 + +From: Piotr Krysiuk + +commit e4d4d456436bfb2fe412ee2cd489f7658449b098 upstream. + +The branch displacement logic in the BPF JIT compilers for x86 assumes +that, for any generated branch instruction, the distance cannot +increase between optimization passes. + +But this assumption can be violated due to how the distances are +computed. Specifically, whenever a backward branch is processed in +do_jit(), the distance is computed by subtracting the positions in the +machine code from different optimization passes. This is because part +of addrs[] is already updated for the current optimization pass, before +the branch instruction is visited. + +And so the optimizer can expand blocks of machine code in some cases. + +This can confuse the optimizer logic, where it assumes that a fixed +point has been reached for all machine code blocks once the total +program size stops changing. And then the JIT compiler can output +abnormal machine code containing incorrect branch displacements. + +To mitigate this issue, we assert that a fixed point is reached while +populating the output image. This rejects any problematic programs. +The issue affects both x86-32 and x86-64. We mitigate separately to +ease backporting. + +Signed-off-by: Piotr Krysiuk +Reviewed-by: Daniel Borkmann +Signed-off-by: Daniel Borkmann +Signed-off-by: Greg Kroah-Hartman +--- + arch/x86/net/bpf_jit_comp.c | 11 ++++++++++- + 1 file changed, 10 insertions(+), 1 deletion(-) + +--- a/arch/x86/net/bpf_jit_comp.c ++++ b/arch/x86/net/bpf_jit_comp.c +@@ -1038,7 +1038,16 @@ common_load: + } + + if (image) { +- if (unlikely(proglen + ilen > oldproglen)) { ++ /* ++ * When populating the image, assert that: ++ * ++ * i) We do not write beyond the allocated space, and ++ * ii) addrs[i] did not change from the prior run, in order ++ * to validate assumptions made for computing branch ++ * displacements. ++ */ ++ if (unlikely(proglen + ilen > oldproglen || ++ proglen + ilen != addrs[i])) { + pr_err("bpf_jit_compile fatal error\n"); + return -EFAULT; + } diff --git a/queue-4.4/cifs-silently-ignore-unknown-oplock-break-handle.patch b/queue-4.4/cifs-silently-ignore-unknown-oplock-break-handle.patch index 67c6fe5505f..de5df26d828 100644 --- a/queue-4.4/cifs-silently-ignore-unknown-oplock-break-handle.patch +++ b/queue-4.4/cifs-silently-ignore-unknown-oplock-break-handle.patch @@ -30,14 +30,12 @@ Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French Signed-off-by: Sasha Levin --- - fs/cifs/smb2misc.c | 4 ++-- + fs/cifs/smb2misc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c -index 44198b9a5315..19baeb4ca511 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c -@@ -633,8 +633,8 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server) +@@ -633,8 +633,8 @@ smb2_is_valid_oplock_break(char *buffer, } } spin_unlock(&cifs_tcp_ses_lock); @@ -48,6 +46,3 @@ index 44198b9a5315..19baeb4ca511 100644 } void --- -2.30.2 - diff --git a/queue-4.4/series b/queue-4.4/series index 11bb37cc3dc..d5340976f75 100644 --- a/queue-4.4/series +++ b/queue-4.4/series @@ -5,3 +5,4 @@ x86-build-turn-off-fcf-protection-for-realmode-targe.patch ia64-mca-allocate-early-mca-with-gfp_atomic.patch cifs-revalidate-mapping-when-we-open-files-for-smb1-.patch cifs-silently-ignore-unknown-oplock-break-handle.patch +bpf-x86-validate-computation-of-branch-displacements-for-x86-64.patch