5.15-stable patches

added patches:
	bpf-ensure-main-program-has-an-extable.patch

diff --git a/queue-5.15/bpf-ensure-main-program-has-an-extable.patch b/queue-5.15/bpf-ensure-main-program-has-an-extable.patch
new file mode 100644 (file)
index 0000000..eb0d9c1
--- /dev/null
+++ b/queue-5.15/bpf-ensure-main-program-has-an-extable.patch
@@ -0,0 +1,64 @@
+From 0108a4e9f3584a7a2c026d1601b0682ff7335d95 Mon Sep 17 00:00:00 2001
+From: Krister Johansen <kjlx@templeofstupid.com>
+Date: Mon, 12 Jun 2023 17:44:40 -0700
+Subject: bpf: ensure main program has an extable
+
+From: Krister Johansen <kjlx@templeofstupid.com>
+
+commit 0108a4e9f3584a7a2c026d1601b0682ff7335d95 upstream.
+
+When subprograms are in use, the main program is not jit'd after the
+subprograms because jit_subprogs sets a value for prog->bpf_func upon
+success.  Subsequent calls to the JIT are bypassed when this value is
+non-NULL.  This leads to a situation where the main program and its
+func[0] counterpart are both in the bpf kallsyms tree, but only func[0]
+has an extable.  Extables are only created during JIT.  Now there are
+two nearly identical program ksym entries in the tree, but only one has
+an extable.  Depending upon how the entries are placed, there's a chance
+that a fault will call search_extable on the aux with the NULL entry.
+
+Since jit_subprogs already copies state from func[0] to the main
+program, include the extable pointer in this state duplication.
+Additionally, ensure that the copy of the main program in func[0] is not
+added to the bpf_prog_kallsyms table. Instead, let the main program get
+added later in bpf_prog_load().  This ensures there is only a single
+copy of the main program in the kallsyms table, and that its tag matches
+the tag observed by tooling like bpftool.
+
+Cc: stable@vger.kernel.org
+Fixes: 1c2a088a6626 ("bpf: x64: add JIT support for multi-function programs")
+Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
+Acked-by: Yonghong Song <yhs@fb.com>
+Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
+Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
+Link: https://lore.kernel.org/r/6de9b2f4b4724ef56efbb0339daaa66c8b68b1e7.1686616663.git.kjlx@templeofstupid.com
+Signed-off-by: Alexei Starovoitov <ast@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/bpf/verifier.c |    7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+--- a/kernel/bpf/verifier.c
++++ b/kernel/bpf/verifier.c
+@@ -12588,9 +12588,10 @@ static int jit_subprogs(struct bpf_verif
+       }
+ 
+       /* finally lock prog and jit images for all functions and
+-       * populate kallsysm
++       * populate kallsysm. Begin at the first subprogram, since
++       * bpf_prog_load will add the kallsyms for the main program.
+        */
+-      for (i = 0; i < env->subprog_cnt; i++) {
++      for (i = 1; i < env->subprog_cnt; i++) {
+               bpf_prog_lock_ro(func[i]);
+               bpf_prog_kallsyms_add(func[i]);
+       }
+@@ -12615,6 +12616,8 @@ static int jit_subprogs(struct bpf_verif
+ 
+       prog->jited = 1;
+       prog->bpf_func = func[0]->bpf_func;
++      prog->aux->extable = func[0]->aux->extable;
++      prog->aux->num_exentries = func[0]->aux->num_exentries;
+       prog->aux->func = func;
+       prog->aux->func_cnt = env->subprog_cnt;
+       bpf_prog_jit_attempt_done(prog);

diff --git a/queue-5.15/series b/queue-5.15/series
index 2bf53fbaa323f576f6e58f41a57a1aace6e5e242..15a4b3343644ca418226d2b591c1d32ac3ccba61 100644 (file)
--- a/queue-5.15/series
+++ b/queue-5.15/series
@@ -6,3 +6,4 @@ drm-amdgpu-set-vmbo-destroy-after-pt-bo-is-created.patch
 x86-microcode-amd-load-late-on-both-threads-too.patch
 x86-smp-use-dedicated-cache-line-for-mwait_play_dead.patch
 can-isotp-isotp_sendmsg-fix-return-error-fix-on-tx-path.patch
+bpf-ensure-main-program-has-an-extable.patch