Commit 4d0c5ba (vfs: do get_write_access() on upper layer of overlayfs)
that was merged for kernel v4.8 changes the behavior of execve+truncate
in a subtle way.
When file is executed from lower and then truncated, the truncation is
allowed, becasue it only affects the size of the copied up file and does
not affect the VM mapping of the executed lower file.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
test_upper file was supposed to be in upper layer,
but it was wrongly created in lower layer.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
Test truncate running executable binaries from lower and upper dirs.
truncate(2) should return ETXTBSY, not other errno nor segfault
Commit 03bea6040932 ("ovl: get_write_access() in truncate") fixed
this issue.
Reviewed-by: Xiong Zhou <xzhou@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
Amir Goldstein
Eryu Guan