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| author | Suren Baghdasaryan <surenb@google.com> | 2025-05-16 17:07:39 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-05-25 00:53:48 -0700 |
| commit | 12ca42c237756182aad8ab04654c952765cb9061 (patch) | |
| tree | 68fcd31ac0e0624091926dc8034f73deede1f4cd /lib/codetag.c | |
| parent | 221fcbf77578826fad8f4bfa0530b5b55bf9676a (diff) | |
| download | linux-12ca42c237756182aad8ab04654c952765cb9061.tar.gz linux-12ca42c237756182aad8ab04654c952765cb9061.tar.bz2 linux-12ca42c237756182aad8ab04654c952765cb9061.zip | |
alloc_tag: allocate percpu counters for module tags dynamically
When a module gets unloaded it checks whether any of its tags are still in
use and if so, we keep the memory containing module's allocation tags
alive until all tags are unused. However percpu counters referenced by
the tags are freed by free_module(). This will lead to UAF if the memory
allocated by a module is accessed after module was unloaded.
To fix this we allocate percpu counters for module allocation tags
dynamically and we keep it alive for tags which are still in use after
module unloading. This also removes the requirement of a larger
PERCPU_MODULE_RESERVE when memory allocation profiling is enabled because
percpu memory for counters does not need to be reserved anymore.
Link: https://lkml.kernel.org/r/20250517000739.5930-1-surenb@google.com
Fixes: 0db6f8d7820a ("alloc_tag: load module tags into separate contiguous memory")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: David Wang <00107082@163.com>
Closes: https://lore.kernel.org/all/20250516131246.6244-1-00107082@163.com/
Tested-by: David Wang <00107082@163.com>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/codetag.c')
| -rw-r--r-- | lib/codetag.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/codetag.c b/lib/codetag.c index 42aadd6c1454..de332e98d6f5 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -194,7 +194,7 @@ static int codetag_module_init(struct codetag_type *cttype, struct module *mod) if (err >= 0) { cttype->count += range_size(cttype, &range); if (cttype->desc.module_load) - cttype->desc.module_load(cttype, cmod); + cttype->desc.module_load(mod, range.start, range.stop); } up_write(&cttype->mod_lock); @@ -333,7 +333,8 @@ void codetag_unload_module(struct module *mod) } if (found) { if (cttype->desc.module_unload) - cttype->desc.module_unload(cttype, cmod); + cttype->desc.module_unload(cmod->mod, + cmod->range.start, cmod->range.stop); cttype->count -= range_size(cttype, &cmod->range); idr_remove(&cttype->mod_idr, mod_id); |