From: Zheng Zengkai <zhengzengkai@huawei.com> From: Jiasheng Jiang <jiasheng@iscas.ac.cn> stable inclusion from stable-v6.6.2 commit ad5cb6deb41417ef41b9d6ff54f789212108606f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8IW7G Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit a19d48f7c5d57c0f0405a7d4334d1d38fe9d3c1c ] Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference. Fixes: 563ca40ddf40 ("pstore/platform: Switch pstore_info::name to const") Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> Link: https://lore.kernel.org/r/20230623022706.32125-1-jiasheng@iscas.ac.cn Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/pstore/platform.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index e5bca9a004cc..03425928d2fb 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -464,6 +464,8 @@ static int pstore_write_user_compat(struct pstore_record *record, */ int pstore_register(struct pstore_info *psi) { + char *new_backend; + if (backend && strcmp(backend, psi->name)) { pr_warn("backend '%s' already in use: ignoring '%s'\n", backend, psi->name); @@ -484,11 +486,16 @@ int pstore_register(struct pstore_info *psi) return -EINVAL; } + new_backend = kstrdup(psi->name, GFP_KERNEL); + if (!new_backend) + return -ENOMEM; + mutex_lock(&psinfo_lock); if (psinfo) { pr_warn("backend '%s' already loaded: ignoring '%s'\n", psinfo->name, psi->name); mutex_unlock(&psinfo_lock); + kfree(new_backend); return -EBUSY; } @@ -521,7 +528,7 @@ int pstore_register(struct pstore_info *psi) * Update the module parameter backend, so it is visible * through /sys/module/pstore/parameters/backend */ - backend = kstrdup(psi->name, GFP_KERNEL); + backend = new_backend; pr_info("Registered %s as persistent store backend\n", psi->name); -- 2.20.1