The following functions call proc_mem_open but do not handle the case where it returns NULL: __mem_open in fs/proc/base.c proc_maps_open in fs/proc/task_mmu.c smaps_rollup_open in fs/proc/task_mmu.c pagemap_open in fs/proc/task_mmu.c maps_open in fs/proc/task_nommu.c The following reported bugs may be related to this issue: https://lore.kernel.org/all/000000000000f52642060d4e3750@xxxxxxxxxx https://lore.kernel.org/all/0000000000001bc4a00612d9a7f4@xxxxxxxxxx Fix: Modify proc_mem_open to return an error code in case of errors, instead of returning NULL. Signed-off-by: Penglei Jiang <superman.xpt@xxxxxxxxx> --- fs/proc/base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index cd89e956c322..b5e7317cf0dc 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -840,7 +840,7 @@ struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) put_task_struct(task); if (IS_ERR(mm)) - return mm == ERR_PTR(-ESRCH) ? NULL : mm; + return mm; /* ensure this mm_struct can't be freed */ mmgrab(mm); -- 2.17.1
