ima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr

Summary

In the Linux kernel, the following vulnerability has been resolved: ima: don't clear IMA_DIGSIG flag when setting or removing non-IMA xattr Currently when both IMA and EVM are in fix mode, the IMA signature will be reset to IMA hash if a program first stores IMA signature in security.ima and then writes/removes some other security xattr for the file. For example, on Fedora, after booting the kernel with "ima_appraise=fix evm=fix ima_policy=appraise_tcb" and installing rpm-plugin-ima, installing/reinstalling a package will not make good reference IMA signature generated. Instead IMA hash is generated, getfattr -m - -d -e hex /usr/bin/bash file: usr/bin/bash security.ima=0x0404... This happens because when setting security.selinux, the IMA_DIGSIG flag that had been set early was cleared. As a result, IMA hash is generated when the file is closed. Similarly, IMA signature can be cleared on file close after removing security xattr like security.evm or setting/removing ACL. Prevent replacing the IMA file signature with a file hash, by preventing the IMA_DIGSIG flag from being reset. Here's a minimal C reproducer which sets security.selinux as the last step which can also replaced by removing security.evm or setting ACL, #include <stdio.h> #include <sys/xattr.h> #include <fcntl.h> #include <unistd.h> #include <string.h> #include <stdlib.h> int main() { const char* file_path = "/usr/sbin/test_binary"; const char* hex_string = "030204d33204490066306402304"; int length = strlen(hex_string); char* ima_attr_value; int fd; fd = open(file_path, O_WRONLY|O_CREAT|O_EXCL, 0644); if (fd == -1) { perror("Error opening file"); return 1; } ima_attr_value = (char*)malloc(length / 2 ); for (int i = 0, j = 0; i < length; i += 2, j++) { sscanf(hex_string + i, "%2hhx", &ima_attr_value[j]); } if (fsetxattr(fd, "security.ima", ima_attr_value, length/2, 0) == -1) { perror("Error setting extended attribute"); close(fd); return 1; } const char* selinux_value= "system_u:object_r:bin_t:s0"; if (fsetxattr(fd, "security.selinux", selinux_value, strlen(selinux_value), 0) == -1) { perror("Error setting extended attribute"); close(fd); return 1; } close(fd); return 0; }

Timeline

1. Dec 16, 2025, 1:43 PM UTCCVE published
2. Oct 15, 2026, 9:59 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 15, 2026, 10:02 PM UTCRecord last updated

Affected versions

• Linux Linux

  From e3ccfe1ad7d895487977ef64eda3441d16c9851a · fixed in d2993a7e98eb70c737c6f5365a190e79c72b8407; From e3ccfe1ad7d895487977ef64eda3441d16c9851a · fixed in edd824eb45e4f7e05ad3ab090dab6dbdb79cd292; From e3ccfe1ad7d895487977ef64eda3441d16c9851a · fixed in 02aa671c08a4834bef5166743a7b88686fbfa023; From e3ccfe1ad7d895487977ef64eda3441d16c9851a · fixed in 88b4cbcf6b041ae0f2fc8a34554a5b6a83a2b7cd

• Linux Linux

  5.14

• KernelLinux

  From 5.14.0 · fixed in 6.6.117; From 6.7.0 · fixed in 6.12.58; From 6.13.0 · fixed in 6.17.8

References 4