From: wangzijie <wangzijie1@honor.com> mainline inclusion from mainline-v6.17-rc1 commit ff7ec8dc1b646296f8d94c39339e8d3833d16c05 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICUC9Z Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Check pde->proc_ops->proc_lseek directly may cause UAF in rmmod scenario. It's a gap in proc_reg_open() after commit 654b33ada4ab("proc: fix UAF in proc_get_inode()"). Followed by AI Viro's suggestion, fix it in same manner. Link: https://lkml.kernel.org/r/20250607021353.1127963-1-wangzijie1@honor.com Fixes: 3f61631d47f1 ("take care to handle NULL ->proc_lseek()") Signed-off-by: wangzijie <wangzijie1@honor.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: fs/proc/inode.c [Commit 133097647206 ("proc: use __auto_type more") removed the definition of release in proc_reg_open().] Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> --- fs/proc/generic.c | 2 ++ fs/proc/inode.c | 2 +- fs/proc/internal.h | 5 +++++ include/linux/proc_fs.h | 1 + 4 files changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index c8785d68e870..2187d9ca351c 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -567,6 +567,8 @@ static void pde_set_flags(struct proc_dir_entry *pde) if (pde->proc_ops->proc_compat_ioctl) pde->flags |= PROC_ENTRY_proc_compat_ioctl; #endif + if (pde->proc_ops->proc_lseek) + pde->flags |= PROC_ENTRY_proc_lseek; } struct proc_dir_entry *proc_create_data(const char *name, umode_t mode, diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 897c71077a0f..957021784026 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -494,7 +494,7 @@ static int proc_reg_open(struct inode *inode, struct file *file) typeof_member(struct proc_ops, proc_release) release; struct pde_opener *pdeo; - if (!pde->proc_ops->proc_lseek) + if (!pde_has_proc_lseek(pde)) file->f_mode &= ~FMODE_LSEEK; if (pde_is_permanent(pde)) { diff --git a/fs/proc/internal.h b/fs/proc/internal.h index d5509cb5019c..464d729ab0c8 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -98,6 +98,11 @@ static inline bool pde_has_proc_compat_ioctl(const struct proc_dir_entry *pde) #endif } +static inline bool pde_has_proc_lseek(const struct proc_dir_entry *pde) +{ + return pde->flags & PROC_ENTRY_proc_lseek; +} + extern struct kmem_cache *proc_dir_entry_cache; void pde_free(struct proc_dir_entry *pde); diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index fdab1d93a5d1..48359f484de0 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -27,6 +27,7 @@ enum { PROC_ENTRY_proc_read_iter = 1U << 1, PROC_ENTRY_proc_compat_ioctl = 1U << 2, + PROC_ENTRY_proc_lseek = 1U << 3, }; struct proc_ops { -- 2.39.2