libkmod: Handle long lines in /proc/modules

kmod_module_new_from_loaded() calls fgets with a 4k buffer. When a
module such as usbcore is used by too many modules, the rest of the line
is considered a beginning of another lines and we eventually get errors
like these from lsmod:

libkmod: kmod_module_get_holders: could not open '/sys/module/100,/holders': No such file or directory

together with bogus entries in the output. In kmod_module_get_size, the
problem does not affect functionality, but the line numbers in error
messages will be wrong.

Signed-off-by: Michal Marek <mmarek@suse.com>

diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 1460c67..25dcda7 100644 (file)
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -1660,13 +1660,14 @@ KMOD_EXPORT int kmod_module_new_from_loaded(struct kmod_ctx *ctx,
                struct kmod_module *m;
                struct kmod_list *node;
                int err;
+               size_t len = strlen(line);
                char *saveptr, *name = strtok_r(line, " \t", &saveptr);
 
                err = kmod_module_new_from_name(ctx, name, &m);
                if (err < 0) {
                        ERR(ctx, "could not get module from name '%s': %s\n",
                                name, strerror(-err));
-                       continue;
+                       goto eat_line;
                }
 
                node = kmod_list_append(l, m);
@@ -1676,6 +1677,9 @@ KMOD_EXPORT int kmod_module_new_from_loaded(struct kmod_ctx *ctx,
                        ERR(ctx, "out of memory\n");
                        kmod_module_unref(m);
                }
+eat_line:
+               while (line[len - 1] != '\n' && fgets(line, sizeof(line), fp))
+                       len = strlen(line);
        }
 
        fclose(fp);
@@ -1825,12 +1829,13 @@ KMOD_EXPORT long kmod_module_get_size(const struct kmod_module *mod)
        }
 
        while (fgets(line, sizeof(line), fp)) {
+               size_t len = strlen(line);
                char *saveptr, *endptr, *tok = strtok_r(line, " \t", &saveptr);
                long value;
 
                lineno++;
                if (tok == NULL || !streq(tok, mod->name))
-                       continue;
+                       goto eat_line;
 
                tok = strtok_r(NULL, " \t", &saveptr);
                if (tok == NULL) {
@@ -1848,6 +1853,9 @@ KMOD_EXPORT long kmod_module_get_size(const struct kmod_module *mod)
 
                size = value;
                break;
+eat_line:
+               while (line[len - 1] != '\n' && fgets(line, sizeof(line), fp))
+                       len = strlen(line);
        }
        fclose(fp);