summary refs log tree commit diff stats
path: root/results/classifier/gemma3:12b/kernel/1824344
diff options
context:
space:
mode:
authorChristian Krinitsin <mail@krinitsin.com>2025-07-03 07:27:52 +0000
committerChristian Krinitsin <mail@krinitsin.com>2025-07-03 07:27:52 +0000
commitd0c85e36e4de67af628d54e9ab577cc3fad7796a (patch)
treef8f784b0f04343b90516a338d6df81df3a85dfa2 /results/classifier/gemma3:12b/kernel/1824344
parent7f4364274750eb8cb39a3e7493132fca1c01232e (diff)
downloademulator-bug-study-d0c85e36e4de67af628d54e9ab577cc3fad7796a.tar.gz
emulator-bug-study-d0c85e36e4de67af628d54e9ab577cc3fad7796a.zip
add deepseek and gemma results
Diffstat (limited to 'results/classifier/gemma3:12b/kernel/1824344')
-rw-r--r--results/classifier/gemma3:12b/kernel/182434446
1 files changed, 46 insertions, 0 deletions
diff --git a/results/classifier/gemma3:12b/kernel/1824344 b/results/classifier/gemma3:12b/kernel/1824344
new file mode 100644
index 00000000..438a32dd
--- /dev/null
+++ b/results/classifier/gemma3:12b/kernel/1824344
@@ -0,0 +1,46 @@
+
+x86: retf or iret pagefault sets wrong error code
+
+With a x86_64 or i386 guest, non-KVM, when trying to execute a
+"iret/iretq/retf" instruction in userspace with invalid stack pointer
+(under a protected mode OS, like Linux), wrong bits are set in the
+pushed error code; bit 2 is not set, indicating the error comes from
+kernel space.
+
+If the guest OS is using this flag to decide whether this was a kernel
+or user page fault, it will mistakenly decide a kernel has irrecoverably
+faulted, possibly causing guest OS panic.
+
+
+How to reproduce the problem a guest (non-KVM) Linux:
+Note, on recent Linux kernel version, this needs a CPU with SMAP support
+(eg. -cpu max)
+
+$ cat tst.c
+int main()
+{
+__asm__ volatile (
+"mov $0,%esp\n"
+"retf"
+);
+return 0;
+}
+
+$ gcc tst.c
+$ ./a.out
+Killed
+
+
+"dmesg" shows the kernel has in fact triggered a "BUG: unable to handle
+kernel NULL pointer dereference...", but it has "recovered" by killing
+the faulting process (see attached screenshot).
+
+
+Using self-compiled qemu from git:
+commit 532cc6da74ec25b5ba6893b5757c977d54582949 (HEAD -> master, tag: v4.0.0-rc3, origin/master, origin/HEAD)
+Author: Peter Maydell <email address hidden>
+Date:   Wed Apr 10 15:38:59 2019 +0100
+
+    Update version for v4.0.0-rc3 release
+    
+    Signed-off-by: Peter Maydell <email address hidden>
\ No newline at end of file