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Wysocki" , Danilo Krummrich , Miguel Ojeda , Kees Cook , Nathan Chancellor Cc: Nick Desaulniers , Bill Wendling , Justin Stitt , Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Nayna Jain , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , Viresh Kumar , David Teigland , Alexander Aring , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Richard Weinberger , Zhihao Cheng , Felix Kuehling , Alex Deucher , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , driver-core@lists.linux.dev, llvm@lists.linux.dev, linux-hardening@vger.kernel.org, linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org, gfs2@lists.linux.dev, xen-devel@lists.xenproject.org, linux-s390@vger.kernel.org, linux-mtd@lists.infradead.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Ian Rogers X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261013_154028_490212_A1B44C79 X-CRM114-Status: GOOD ( 14.48 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org struct dlm_ls embeds a struct kobject (ls_kobj), but dlm_ktype lacked a .release callback and dlm freed the lockspace structure directly via kfree(ls). With CONFIG_DEBUG_KOBJECT_RELEASE=y, freeing ls before the kobject release runs causes a use-after-free. Add dlm_ls_release() to free struct dlm_ls when the last reference to ls_kobj is dropped, use kobject_del() in release_lockspace(), and drop the final kobject reference in free_lockspace(). Fixes: 3514faca19a6 ("kobject: remove struct kobj_type from struct kset") Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Ian Rogers --- fs/dlm/lockspace.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index a9c98b4f378f..1d226b27d8e6 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -179,7 +179,15 @@ static const struct sysfs_ops dlm_attr_ops = { .store = dlm_attr_store, }; +static void dlm_ls_release(struct kobject *kobj) +{ + struct dlm_ls *ls = container_of(kobj, struct dlm_ls, ls_kobj); + + kfree(ls); +} + static struct kobj_type dlm_ktype = { + .release = dlm_ls_release, .default_groups = dlm_groups, .sysfs_ops = &dlm_attr_ops, }; @@ -355,7 +363,7 @@ static void free_lockspace(struct work_struct *work) */ rhashtable_free_and_destroy(&ls->ls_rsbtbl, rhash_free_rsb, NULL); - kfree(ls); + kobject_put(&ls->ls_kobj); } static int new_lockspace(const char *name, const char *cluster, @@ -436,6 +444,8 @@ static int new_lockspace(const char *name, const char *cluster, atomic_set(&ls->ls_count, 0); init_waitqueue_head(&ls->ls_count_wait); ls->ls_flags = 0; + ls->ls_kobj.kset = dlm_kset; + kobject_init(&ls->ls_kobj, &dlm_ktype); if (ops && dlm_config.ci_recover_callbacks) { ls->ls_ops = ops; @@ -567,9 +577,7 @@ static int new_lockspace(const char *name, const char *cluster, wait_event(ls->ls_recover_lock_wait, test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags)); - ls->ls_kobj.kset = dlm_kset; - error = kobject_init_and_add(&ls->ls_kobj, &dlm_ktype, NULL, - "%s", ls->ls_name); + error = kobject_add(&ls->ls_kobj, NULL, "%s", ls->ls_name); if (error) goto out_recoverd; kobject_uevent(&ls->ls_kobj, KOBJ_ADD); @@ -615,7 +623,6 @@ static int new_lockspace(const char *name, const char *cluster, rhashtable_destroy(&ls->ls_rsbtbl); out_lsfree: kobject_put(&ls->ls_kobj); - kfree(ls); out: module_put(THIS_MODULE); return error; @@ -759,7 +766,7 @@ static int release_lockspace(struct dlm_ls *ls, unsigned int release_option) dlm_delete_debug_file(ls); - kobject_put(&ls->ls_kobj); + kobject_del(&ls->ls_kobj); xa_destroy(&ls->ls_recover_xa); kfree(ls->ls_recover_buf); -- 2.56.0.385.gd3acb90ef8-goog ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/