On Mon, Oct 16, 2023 at 05:32:00PM +0100, Lorenzo Stoakes wrote:
On Mon, Oct 16, 2023 at 12:05:37PM +0100, Lorenzo Stoakes wrote:
On Mon, Oct 16, 2023 at 03:52:07PM +0530, Naresh Kamboju wrote:
Following kernel crash noticed while running LTP hugetlb and selftests on qemu-x86_64 and qemu-arm64 running with Linux next 6.6.0-rc6-next-20231016.
Reported-by: Linux Kernel Functional Testing lkft@linaro.org Reported-by: Naresh Kamboju naresh.kamboju@linaro.org
Test Logs:
[snip]
<4>[ 97.499871] Call trace: <4>[ 97.500288] mmap_region (include/linux/fs.h:580 mm/mmap.c:2946)
OK this is from a patch of mine, and an easy fix (incorrect assumption about vm->vm_file == file).
I will put a fix forward tonight.
<4>[ 97.500814] do_mmap (mm/mmap.c:1379) <4>[ 97.501243] vm_mmap_pgoff (mm/util.c:546) <4>[ 97.501711] ksys_mmap_pgoff (mm/mmap.c:1425) <4>[ 97.502166] __arm64_sys_mmap (arch/arm64/kernel/sys.c:21) <4>[ 97.502634] invoke_syscall (arch/arm64/include/asm/current.h:19 arch/arm64/kernel/syscall.c:56) <4>[ 97.503175] el0_svc_common.constprop.0 (include/linux/thread_info.h:127 (discriminator 2) arch/arm64/kernel/syscall.c:144 (discriminator 2)) <4>[ 97.503763] do_el0_svc (arch/arm64/kernel/syscall.c:156) <4>[ 97.504191] el0_svc (arch/arm64/include/asm/daifflags.h:28 arch/arm64/kernel/entry-common.c:133 arch/arm64/kernel/entry-common.c:144 arch/arm64/kernel/entry-common.c:679)
[snip]
Have cc-d people in this thread on it, but for the record, -fix patch is at https://lore.kernel.org/all/c9eb4cc6-7db4-4c2b-838d-43a0b319a4f0@lucifer.loc...
Smatch also caught this bug. Your patch silences the warning.
mm/mmap.c:2946 mmap_region() error: we previously assumed 'file' could be null (see line 2849)
It's amazing that Naresh was able to hit this after it had only been in linux-next for less than a day.
regards, dan carpenter