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| author | Nick Piggin <npiggin@suse.de> | 2007-03-06 13:34:25 +0300 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2007-03-07 01:49:52 +0300 |
| commit | 41d5e5d73ecef4ef56b7b4cde962929a712689b4 (patch) | |
| tree | 51cb9289609c639d86a768ff92340291a4d1b452 /arch/ia64 | |
| parent | 50157b09b33c2ec3637d3b317b06a7235c57c7f2 (diff) | |
| download | linux-41d5e5d73ecef4ef56b7b4cde962929a712689b4.tar.xz | |
[IA64] permon use-after-free fix
Perfmon associates vmalloc()ed memory with a file descriptor, and installs
a vma mapping that memory. Unfortunately, the vm_file field is not filled
in, so processes with mappings to that memory do not prevent the file from
being closed and the memory freed. This results in use-after-free bugs and
multiple freeing of pages, etc.
I saw this bug on an Altix on SLES9. Haven't reproduced upstream but it
looks like the same issue is there.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/kernel/perfmon.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c index 9ddf896a137a..abc7ad035886 100644 --- a/arch/ia64/kernel/perfmon.c +++ b/arch/ia64/kernel/perfmon.c @@ -2299,7 +2299,7 @@ pfm_remap_buffer(struct vm_area_struct *vma, unsigned long buf, unsigned long ad * allocate a sampling buffer and remaps it into the user address space of the task */ static int -pfm_smpl_buffer_alloc(struct task_struct *task, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr) +pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr) { struct mm_struct *mm = task->mm; struct vm_area_struct *vma = NULL; @@ -2349,6 +2349,7 @@ pfm_smpl_buffer_alloc(struct task_struct *task, pfm_context_t *ctx, unsigned lon * partially initialize the vma for the sampling buffer */ vma->vm_mm = mm; + vma->vm_file = filp; vma->vm_flags = VM_READ| VM_MAYREAD |VM_RESERVED; vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */ @@ -2387,6 +2388,8 @@ pfm_smpl_buffer_alloc(struct task_struct *task, pfm_context_t *ctx, unsigned lon goto error; } + get_file(filp); + /* * now insert the vma in the vm list for the process, must be * done with mmap lock held @@ -2464,7 +2467,7 @@ pfarg_is_sane(struct task_struct *task, pfarg_context_t *pfx) } static int -pfm_setup_buffer_fmt(struct task_struct *task, pfm_context_t *ctx, unsigned int ctx_flags, +pfm_setup_buffer_fmt(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned int ctx_flags, unsigned int cpu, pfarg_context_t *arg) { pfm_buffer_fmt_t *fmt = NULL; @@ -2505,7 +2508,7 @@ pfm_setup_buffer_fmt(struct task_struct *task, pfm_context_t *ctx, unsigned int /* * buffer is always remapped into the caller's address space */ - ret = pfm_smpl_buffer_alloc(current, ctx, size, &uaddr); + ret = pfm_smpl_buffer_alloc(current, filp, ctx, size, &uaddr); if (ret) goto error; /* keep track of user address of buffer */ @@ -2716,7 +2719,7 @@ pfm_context_create(pfm_context_t *ctx, void *arg, int count, struct pt_regs *reg * does the user want to sample? */ if (pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) { - ret = pfm_setup_buffer_fmt(current, ctx, ctx_flags, 0, req); + ret = pfm_setup_buffer_fmt(current, filp, ctx, ctx_flags, 0, req); if (ret) goto buffer_error; } |