| Message ID | 20240510100131.1865-1-hailong.liu@oppo.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL | expand |
On Fri, May 10, 2024 at 10:01 PM <hailong.liu@oppo.com> wrote: > > From: "Hailong.Liu" <hailong.liu@oppo.com> > > commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc") > includes support for __GFP_NOFAIL, but it presents a conflict with > commit dd544141b9eb ("vmalloc: back off when the current task is > OOM-killed"). A possible scenario is as follows: > > process-a > __vmalloc_node_range(GFP_KERNEL | __GFP_NOFAIL) > __vmalloc_area_node() > vm_area_alloc_pages() > --> oom-killer send SIGKILL to process-a > if (fatal_signal_pending(current)) break; > --> return NULL; > > To fix this, do not check fatal_signal_pending() in vm_area_alloc_pages() > if __GFP_NOFAIL set. > > Fixes: 9376130c390a ("mm/vmalloc: add support for __GFP_NOFAIL") > Cc: <stable@vger.kernel.org> > Acked-by: Michal Hocko <mhocko@suse.com> > Suggested-by: Barry Song <21cnbao@gmail.com> > Reported-by: Oven <liyangouwen1@oppo.com> > Signed-off-by: Hailong.Liu <hailong.liu@oppo.com> Reviewed-by: Barry Song <baohua@kernel.org> > --- > mm/vmalloc.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 125427cbdb87..109272b8ee2e 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -3492,7 +3492,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > { > unsigned int nr_allocated = 0; > gfp_t alloc_gfp = gfp; > - bool nofail = false; > + bool nofail = gfp & __GFP_NOFAIL; > struct page *page; > int i; > > @@ -3549,12 +3549,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > * and compaction etc. > */ > alloc_gfp &= ~__GFP_NOFAIL; > - nofail = true; > } > > /* High-order pages or fallback path if "bulk" fails. */ > while (nr_allocated < nr_pages) { > - if (fatal_signal_pending(current)) > + if (!nofail && fatal_signal_pending(current)) > break; > > if (nid == NUMA_NO_NODE) > ---
On Fri, May 10, 2024 at 06:01:31PM +0800, hailong.liu@oppo.com wrote: > From: "Hailong.Liu" <hailong.liu@oppo.com> > > commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc") > includes support for __GFP_NOFAIL, but it presents a conflict with > commit dd544141b9eb ("vmalloc: back off when the current task is > OOM-killed"). A possible scenario is as follows: > > process-a > __vmalloc_node_range(GFP_KERNEL | __GFP_NOFAIL) > __vmalloc_area_node() > vm_area_alloc_pages() > --> oom-killer send SIGKILL to process-a > if (fatal_signal_pending(current)) break; > --> return NULL; > > To fix this, do not check fatal_signal_pending() in vm_area_alloc_pages() > if __GFP_NOFAIL set. > > Fixes: 9376130c390a ("mm/vmalloc: add support for __GFP_NOFAIL") > Cc: <stable@vger.kernel.org> > Acked-by: Michal Hocko <mhocko@suse.com> > Suggested-by: Barry Song <21cnbao@gmail.com> > Reported-by: Oven <liyangouwen1@oppo.com> > Signed-off-by: Hailong.Liu <hailong.liu@oppo.com> > --- > mm/vmalloc.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 125427cbdb87..109272b8ee2e 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -3492,7 +3492,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > { > unsigned int nr_allocated = 0; > gfp_t alloc_gfp = gfp; > - bool nofail = false; > + bool nofail = gfp & __GFP_NOFAIL; > struct page *page; > int i; > > @@ -3549,12 +3549,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > * and compaction etc. > */ > alloc_gfp &= ~__GFP_NOFAIL; > - nofail = true; > } > > /* High-order pages or fallback path if "bulk" fails. */ > while (nr_allocated < nr_pages) { > - if (fatal_signal_pending(current)) > + if (!nofail && fatal_signal_pending(current)) > break; > > if (nid == NUMA_NO_NODE) > --- > Changes since RFC v1 [1]: > - Remove RFC tag > - Add fixes, per Michal > - Use nofail instead of gfp & __GFP_NOFAIL, per Barry & Michal > - Modify commit log, per Barry > > [1] https://lore.kernel.org/all/20240508125808.28882-1-hailong.liu@oppo.com/ > > This issue occurred during OPLUS KASAN TEST. Below is part of the log > -> oom-killer sends signal to process > [65731.222840] [ T1308] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/apps/uid_10198,task=gs.intelligence,pid=32454,uid=10198 > > [65731.259685] [T32454] Call trace: > [65731.259698] [T32454] dump_backtrace+0xf4/0x118 > [65731.259734] [T32454] show_stack+0x18/0x24 > [65731.259756] [T32454] dump_stack_lvl+0x60/0x7c > [65731.259781] [T32454] dump_stack+0x18/0x38 > [65731.259800] [T32454] mrdump_common_die+0x250/0x39c [mrdump] > [65731.259936] [T32454] ipanic_die+0x20/0x34 [mrdump] > [65731.260019] [T32454] atomic_notifier_call_chain+0xb4/0xfc > [65731.260047] [T32454] notify_die+0x114/0x198 > [65731.260073] [T32454] die+0xf4/0x5b4 > [65731.260098] [T32454] die_kernel_fault+0x80/0x98 > [65731.260124] [T32454] __do_kernel_fault+0x160/0x2a8 > [65731.260146] [T32454] do_bad_area+0x68/0x148 > [65731.260174] [T32454] do_mem_abort+0x151c/0x1b34 > [65731.260204] [T32454] el1_abort+0x3c/0x5c > [65731.260227] [T32454] el1h_64_sync_handler+0x54/0x90 > [65731.260248] [T32454] el1h_64_sync+0x68/0x6c > > [65731.260269] [T32454] z_erofs_decompress_queue+0x7f0/0x2258 > --> be->decompressed_pages = kvcalloc(be->nr_pages, sizeof(struct page *), GFP_KERNEL | __GFP_NOFAIL); > kernel panic by NULL pointer dereference. > erofs assume kvmalloc with __GFP_NOFAIL never return NULL. > [65731.260293] [T32454] z_erofs_runqueue+0xf30/0x104c > [65731.260314] [T32454] z_erofs_readahead+0x4f0/0x968 > [65731.260339] [T32454] read_pages+0x170/0xadc > [65731.260364] [T32454] page_cache_ra_unbounded+0x874/0xf30 > [65731.260388] [T32454] page_cache_ra_order+0x24c/0x714 > [65731.260411] [T32454] filemap_fault+0xbf0/0x1a74 > [65731.260437] [T32454] __do_fault+0xd0/0x33c > [65731.260462] [T32454] handle_mm_fault+0xf74/0x3fe0 > [65731.260486] [T32454] do_mem_abort+0x54c/0x1b34 > [65731.260509] [T32454] el0_da+0x44/0x94 > [65731.260531] [T32454] el0t_64_sync_handler+0x98/0xb4 > [65731.260553] [T32454] el0t_64_sync+0x198/0x19c > -- > 2.34.1 > Makes sense to me: Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> -- Uladzislau Rezki
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 125427cbdb87..109272b8ee2e 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3492,7 +3492,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, { unsigned int nr_allocated = 0; gfp_t alloc_gfp = gfp; - bool nofail = false; + bool nofail = gfp & __GFP_NOFAIL; struct page *page; int i; @@ -3549,12 +3549,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, * and compaction etc. */ alloc_gfp &= ~__GFP_NOFAIL; - nofail = true; } /* High-order pages or fallback path if "bulk" fails. */ while (nr_allocated < nr_pages) { - if (fatal_signal_pending(current)) + if (!nofail && fatal_signal_pending(current)) break; if (nid == NUMA_NO_NODE)